iWLESslli 


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LABORATORY  LESSONS   IN  GENERAL 
SCIENCE 


THE  MACMILLAN  COMPANY 

NEW  YORK    •    BOSTON  •    CHICAGO  •    DALLAS 
ATLANTA  •    SAN   FRANCISCO 

MACMILLAN  &  CO.,  LIMITED 

LONDON  •    BOMBAY  •    CALCUTTA 
MELBOURNE 

THE  MACMILLAN  CO.  OF  CANADA,  LTD, 

TORONTO 


LABORATORY  LESSONS 

IN 

GENERAL  SCIENCE 


BY 


HERBERT   BROWNELL,   B.Sc. 

PROFESSOR  OP  SCIENCES  IN  SECONDARY  EDUCATION  ;   AUTHOR  OF 
"LESSONS  IN  PHYSICS,"  AND  "LESSONS  IN  CHEMISTRY" 

TEACHERS    COLLEGE,    UNIVERSITY    OF    NEBRASKA 
LINCOLN,    NEBRASKA 


THE   MACMILLAN   COMPANY 
1917 

All  rights  reserved 


COPTBIGHT,  1916, 

BT  THE  MACMILLAN  COMPANY. 


Set  up  and  clectrotyped.    Published  June,  1916.     Reprinted 
September,  1916;  January,  1917. 


Kotfnooti  liiressg 

J.  S.  Cushiag  Co.  —  Berwick  &  Smith  Co. 
No, -wood,  Mass.,  U.S.A. 


PREFACE 

THIS  set  of  laboratory  exercises  in  general  science  is  an 
outgrowth  of  courses  given  by  the  author  in  methods  of 
teaching  secondary  school  sciences.  Some  of  the  lessons 
represent  the  combined  efforts  of  a  class  upon  an  assigned 
topic,  but  so  reshaped  that  credit  to  any  individual  is  out 
of  question.  Free  use  has  been  made  of  material  from 
the  author's  Lessons  in  Astronomy,  Chemistry,  Nature 
Study,  and  Physics  —  manuals  prepared  for  his  own  class 
work.  Many  of  the  exercises  have  enough  material  for 
more  than  one  lesson,  and  should  be  subdivided  to  suit 
teaching  conditions. 

The  preparation  of  these  lessons  was  stimulated  by  the 
belief  that  one  chief  cause  of  failure  to  get  desired  results 
with  beginning  classes  in  the  high  school  sciences  lay  in 
the  character  of  the  material  chosen.  It  was  believed 
possible  to  bring  together  from  scattered  sources  that 
which  would  appeal  to  beginners  and  which  would  find 
its  unity  in  their  life  experiences  and  interests.  This 
involved  the  rejection  of  much  material  of  great  worth 
from  the  differentiated  high  school  sciences  that  is  un- 
suited  for  an  elementary  course.  Teachers  subject  to  the 
exactions  of  schoolroom  service  do  not  have  the  time  to 
make  selections  of  material  and  properly  to  relate  and 
adapt  them  for  use. 

The  fund  of  life  experiences  available  for  a  laboratory 
course  about  which  science  instruction  of  a  general  and 

3G0474 


VI  PREFACE 

elementary  nature  may  center  is  large  and  should  be  more 
freely  used  by  science  teachers  in  secondary  schools. 
These  life  experiences,  supplemented  by  the  experimental 
knowledge  gained  under  direction  in  school,  makes  possible 
a  fuller  understanding  of  the  teachings  of  books  and  a 
ready  acquisition  and  grouping  of  a  wide  range  of  facts. 

The  emphasis  placed  in  these  lessons  upon  the  interests 
of  the  individual,  in  both  their  personal  and  their  com- 
munity aspects,  is  expression  of  a  conviction  on  the  part 
of  the  author  that  topics  of  social  science  should  not  only 
be  included  in  a  general  science  course  but  should  be 
treated  in  much  the  same  way  as  are  topics  from  the 
various  fields  of  the  natural  sciences.  Any  unification  of 
life  interests  and  life  problems  with  the  spirit  and  pro- 
cedure in  science  studies  not  only  enriches  the  science 
teaching  but  reacts  upon  the  daily  living  to  make- it  more 
sane  and  more  wisely  ordered. 

School  work  that  requires  discrimination  in  the  impor- 
tance of  the  facts  involved  in  the  affairs  of  life,  that  notes 
the  bearing  of  these  facts  upon  the  well-being  of  the  indi- 
vidual, and  that  formulates  a  rational  course  of  action, 
not  only  develops  a  scientific  attitude  but  it  constitutes  a 
training  of  inestimable  worth  in  the  education  of  youth. 
The  varied  interests  of  pupils  are  thus  made  centers  about 
which  to  group  newly  acquired  knowledge. 

It  is  the  author's  belief  that  differentiation  between  the 
various  sciences  may  be  disregarded  during  the  first  year 
in  high  school.  Emphasis  is  placed  instead  upon  an  inter- 
pretation of  related  scientific  phenomena  regardless  of  the 
fields  into  which  any  inquiry  may  lead.  The  relationship 
and  unity  indispensable  in  science  studies  is  secured 
through  a  grouping  of  the  interests  and  experiences  of  the 


PREFACE  Vli 

pupils  rather  than  in  the  principles  and  laws  of  any  branch 
of  science.  And  it  has  been  the  aim  to  select  as  material 
for  study  not  only  that  which  is  valuable  in  itself  but  that 
which  at  the  same  time  is  likely  to  be  a  stimulus  in  a  truly 
educative  process. 

The  author  wishes  to  express  his  appreciation  of  the 
helpful  suggestions  and  criticisms  coming  from  those  who 
have  read  the  manuscript  of  these  lessons.  He  desires 
especially  to  thank  Professor  George  E.  Martin,  Head  of 
the  Department  of  English  in  the  State  Normal  School  at 
Kearney ;  and  Dr.  R.  J.  Pool,  Professor  of  Botany  in  the 
State  University  at  Lincoln.  He  is  greatly  indebted,  too, 
for  helpful  suggestions  from  the  following  who  have  read 
portions  of  the  manuscript  :  Miss  Alice  Loomis,  Head  of 
the  Department  of  Home  Economics  at  the  State  Univer- 
sity of  Nebraska ;  George  E.  Loveland,  Professor  of 
Meteorology  in  the  State  University  and  Director  of  the 
U.  S.  Weather  Bureau ;  Dean  E.  L.  Rouse,  Superintend- 
ent of  Practice  in  the  State  Normal  School  at  Peru ; 
Professor  H.  C.  Filley,  Head  of  the  Department  of  Farm 
Management  in  the  College  of  Agriculture  ;  and  Professor 
B.  C.  Hendricks  of  the  Department  of  Physics  in  the 
State  Normal  School  at  Peru. 

HERBERT  BROWNELL. 

LINCOLN,  NEBRASKA. 
1916. 


CONTENTS 

Lessons  marked  with  an  asterisk  [*]  are  somewhat  more  difficult  than  the  others,  and 
may  when  desired  be  deferred  or  omitted.     Usually  this  will  be  unnecessary. 

PAGE 

I.     THE  HUMAN  BODY    .        .        .        .    »    1 

The  hand.  —  The  mouth.  —  The  eye. 

II.     HEAT  IN  RELATION  TO  THE  HUMAN  BODY       .        9 

Combustion.  —  Ventilation.  —  Respiration.  —  The  human 
body  as  an  engine.  — Regulation  of  the  body  temperature. 

III.     HEALTH  AND  WELL-BEING    ...      19 

Keeping  well.  —  Infection.  —  Sanitation.  —  The  water  supply 
and  health.  —  General  health  problems.  —  Life,  growth,  rest, 
and  recreation.  —  Stimulants  and  narcotics.  —  General  science 
and  right  living. 

IV.  MATTER  AND  FORCE         .        ...      38 
Some  properties  of  matter,  and  changes  in  matter  due  to  force. 

V.  WATER  AND  ITS  USES        ...      41 

Some  properties  of  water.  —  Vaporization  and  condensation. 
—  Heat  of  vaporization  and  of  fusion.  —  Solution,  absorption, 
and  diffusion.  —  Osmosis  in  the  body  and  in  plants.  —  Study  of 
a  stream.  —  Valley  formation  and  surface  erosion. 

• 

VI.     THE  ATMOSPHERE  ....      53 

Some  properties  and  uses  of  air.  —  Pressure  exerted  by  the 
atmosphere.  —  Applications  of  atmospheric  pressure.  —  Causes 
of  change  in  atmospheric  pressure.  —  Currents  in  the  atmos- 
phere. —  Areas  of  high  and  low  pressure.* 


X  CONTENTS 

PAGE 

VII.    WEATHER  AND  CLIMATE    ...      63 

Weather  in  the  affairs  of  men.  —  Weather  as  affected  by  highs 
and  lows.*  —  The  thermometer.  —  Temperature  records.  —  Solar 
heating.*  General  weather  records.* 


VIII.    AT  OUR  HOMES  ....      77 

Rooms  of  the  house  and  their  furnishings.  —  The  cost  of  liv- 
ing. —  Fires  and  burns.  —  Accidents  other  than  burns. 


IX.     HOUSEHOLD  CHEMISTRY      ...      94 

A  review  of  some  chemical  changes.  —  The  chemistry  of  clean- 
ing. —  Acids,  bases,  and  salts.  —  Some  carbonates.* 


X.    THE  HOME  SURROUNDINGS     .        .        .    101 

A  garden  in  the  life  of  a  family.  —  The  care  of  a  garden.— 
Tree  planting.  —  Trees  of  the  neighborhood.  —  Some  plant 
studies.  —  Birds  about  our  homes. 


XL    LOCAL  INDUSTRIES  ....    117 

Some  occupations   of  the  community.  —  Modern  industrial 
life.  —  Sanitary  conditions  for  the  wage  earner. 


XII.    THE  FARM,  AND  OUR  FOOD  SUPPLIES         .    124 

The  hen.  —  Eggs.  —  Poultry  keeping.  —  The  horse.  —  Cows 
and  the  dairy  industry.  —  Some  foodstuffs.  —  Lessons  on  corn.  — 
Fruits,  and  apple  raising  as  an  industry.  —  Wheat  and  wheat 
growing.  —  Other  foodstuffs.  —  Origin  and  nature  of  soils. — 
Soil  conditions  in  plant  growth.  —  Usefulness  of  plants  to  man. 

XIII.    WORK  AND  MACHINES      .        .        .160 

Meaning  of  the  terms  work  and  energy.  —  Measurement  of 
work  and  energy.  —  Classes  of  levers.  —  Pulleys.* 


CONTENTS  XI 


PAGE 


XIV.    MAGNETISM  AND  ELECTRICITY       .        .    167 
Electromagnets.  —  Electricity  and  chemical  changes. 

XV.    PHENOMENA  OF  LIGHT      .        .        .172 

Shadows  and  eclipses.*  —  Images  by  reflection.  —  Color  phe- 
nomena.* 

XVI.     THE  EARTH  AS  A  PLANET  .        .        .180 

Day  and  night  and  the  earth's  rotation.  —  Rotation  combined 
with  revolution  and  changes  in  seasons.*  —  The  moon  and  its 
phenomena.  —  Time  and  time-keeping,  and  standard  time.* 

XVII.    THE  HEAVENS*  ....     193 


SUGGESTIONS  TO  TEACHERS 

FROM  his  own  observations  and  experiences  the  author 
ventures  the  following  suggestions  with  the  hope  that  they 

may  be  of  assistance  to  teachers  generally. 

• 

I.     LABORATORY  EXERCISES 

1.  The  laboratory  requirements  should  demand  no  large 
degree  of  skill  in  manipulation  of  apparatus.     In  some  of 
the  lessons,  better  results  will  be  attained  if  the  teacher 
performs  part  or  all  of  the  experiments.     Every  exercise 
should  be  so  shaped  that  it  not  only  challenges  attention 
to  its  results,  but  provokes  inquiry  concerning  the  mean- 
ing of  what  is  noted.     At  all  times  large  use  should  be 
made  of  the  experiences  of  the  pupils  in  order  to  secure  a 
comprehension  of  experimental  phenomena  and  an  under- 
standing of  every  new  requirement  of  the  lessons. 

2.  Very  satisfactory  results   are   attained   where  one 
period  is  given  over  to  a  discussion  of  the  requirements 
of  a  laboratory  exercise  item  by  item  without  previous  study 
having  been  required  of  the  pupils.     In  this  way  there  is  in 
the  class  discussions  a  zest  that  comes  from  having  some- 
thing new,  something  that  has  not  before  been  "  studied." 
The  common  experiences  of  pupils  and  what  has  been 
learned  in  previous  lessons  afford  ample  preparation  for 
such  discussions.      In  this  way  it  becomes  possible  not 
only  to  assemble  and  organize  the  knowledge  possessed  by 

xiii 


xiv  SUGGESTIONS   TO    TEACHERS 

all  the  pupils,  but  to  get  before  the  individual  pupils  the 
results  of  the  class  thought  as  corrected  and  related  under 
guidance  of  the  teacher.  A  second  period  spent  in  the 
laboratory  or  elsewhere  can  then  be  given  over  to  writing 
the  results  of  these  requirements,  with  such  use  of  refer- 
ence books  as  shall  make  this  second  period  a  study  period 
even  as  was  the  first.  These  "  laboratory  papers,"  when 
returned  to  the  pupils,  should  be  preserved  by  them  as 
their  notebooks. 

3.  Assistance  given   pupils   during  these,  preparation 
(laboratory)  hours  may  be  of  such  nature  that  a  consistent 
training  in  the  neglected  art  of  study  is  secured.     To 
learn  whence  to  get  desired  information,  whether  from 
books  or  from  experimental  data,  and  how  best  to  proceed 
in  acquiring  it,  ought  to  be  one  of  the  large  factors  in  an 
education. 

4.  Some  of  the  papers  handed  in  at  the  close  of  every 
laboratory  period  must   be  carefully  reviewed   and   cor- 
rected.    All  should1  be  returned  to  the  pupils  before  the 
next  class  period,  some  of  them  being  marked  "  Not  re- 
viewed "  when  necessary.      There  is  no  more  important 
means  of  securing  information  concerning  the  ability  of 
individual  pupils,  and  no  better  guide  to  teaching  pro- 
cedure, than  is  found  in  the  review  of  some  laboratory 
papers  out  of  every  set  handed  in.     Often  it  is  well  to 
look  over  the  papers  of  the  same  pupil  every  time  for  a 
while. 

II.     CLASS  WORK 

• 

All  corrections  and  explanations  of  a  general  nature 
found  necessary  in  a  review  of  the  laboratory  papers 
should  be  made  by  the  teacher  during  the  class  period. 


SUGGESTIONS   TO   TEACHERS  XV 

Here  is  an  unexcelled  opportunity  to  impart  much  infor- 
mation that  is  closely  related  to  what  has  been  learned. 
Additional  simple  but  instructive  experiments  by  the 
teacher  may  be  introduced  here.  The  class-knowledge 
of  each  topic,  whether  gained  from  experience,  learned  in 
the  laboratory,  or  gathered  from  books,  is  to  be  associated 
and  unified  by  the  teacher.  If  the  laboratory  hour  be 
regarded  as  a  time  of  preparation  for  instruction,  the 
succeeding  class  period  is  a  time  for  teaching. 

When  a  textbook  is  used,  or  any  large  amount  of  refer- 
ence reading  is  assigned,  the  teaching  plan  must  provide 
for  class  periods  given  over  more  or  less  to  quizzes  upon 
the  assignment,  and  to  discussions  and  explanations  to 
make  sure  that  the  readings  are  understood. 


LABORATORY    LESSONS    IN    GENERAL 
SCIENCE 

I.  LESSONS  ON  THE  HUMAN  BODY 

To  THE  PUPIL.  —  In  the  lessons  that  follow  much  useful  information 
may  be  learned  about  many  things  with  which  we  are  already  more  or 
less  acquainted.  Wherever  it  is  possible  we  shall  study  these  things 
directly,  and  try  to  answer  important  questions  about  them.  To  the 
information  gained  in  this  way  we  shall  in  many  cases  add  the  knowl- 
edge gained  from  books.  From  these  observations,  from  experiments, 
and  from  books,  we  are  to  get  all  the  information  we  can.  Every  ques- 
tion asked  and  every  requirement  made  is  of  the  nature  of  a  problem 
for  us  to  solve.  We  are  expected  to  find  a  reasonable  answer  for  it. 
Sometimes  we  shall  want  to  know  not  only  that  a  certain  thing  is  true, 
but  why  it  is  true,  and  what  difference  it  would  make  to  us  if  it  were 
not  true.  That  means  that  we  must  not  only  learn  the  facts,  but  we 
must  consider  what  they  mean.  The  questions  asked  will  guide  us  in 
doing  this.  Doubtless  many  other  questions  will  occur  to  you  whose 
answers  you  will  want  to  know.  Consult  freely  all  books  at  hand 
likely  to  give  the  information  you  want. 

THE  HAND 

I.1  Which  part  of  the  arm  as  a  whole  is  the  hand  ?  What 
name  is  given  the  part  where  the  hand  joins  the  forearm  ? 

2.  After  moving  the  fingers  in  all  possible  directions,  state 
what  is  true  (a)  of  the  freedom  and  variety  in  their  move- 
ments; (6)  of  the  number  of  muscles  required  for  these 
movements. 

1  In  these  laboratory  exercises  the  paragraph  numbering  is  to  be  observed 
in  the  written  work  handed  in.      This  will  aid  in  the  correction  of  the  papers. 
B  1 


2    '-LABORATORY   LESSONS   IN  GENERAL  SCIENCE 

'  3.   While.  t'ic  left  wrist  is  held  in  a  close  grasp  by  the  right 
hand,   observe  any  movements  through  the  wrist  as  the 
fingers   of  the   left   hand  are  moved 
about.     Explain  what  is  seen  and  felt. 
Take  firm  hold  of  the  forearm  just 
below  the  elbow;    move  the  fingers 
freely,    and   explain   any   movements 
noted  in  the  arm.     What  purposes  are 
served  by  having  these  muscles  so  far 
away  from  the  parts  moved  by  them  ? 

4.   By  what  other  means  than  the 

Tendon. 

use   or   many   muscles  is    variety   in 


movements  of  the  hand  secured? 
Count  the  bones  (a)  in  each  finger, 
and  in  the  thumb;  (6)  across  the 
Muscle,  fS^SBIlH  thick  part  of  the  hand.  What  pur- 
poses are  served  (a)  by  binding  to- 
gether the  bones  forming  the  palm 
of  the  hand ;  (6)  by  having  the  thumb 
so  loosely  connected?  What  advan- 
tage results  from  having  one  less 
bone  in  the  thumb  than  in  a  finger? 

FIG.  1. —  Muscles  and  ten- 
dons  of  the  hand  and  Txn  •  .Li- 
forearm.                             5.    What  name  is  given  to  the  inner 

side  of  the  thick  part  of  the  hand? 
What,  is  the  name  given  to  the  union  of  any  two 
bones?  What  special  name  is  given  the  places  where 
the  fingers  are  joined  to  the  hand  ?  What  kind  of  motion 
only  is  possible  in  the  joints  of  a  finger?  Wliat  purpose 
is  served  by  these  limitations  in  the  freedom  of  finger 
movements  ? 


LESSONS  ON   THE  HUMAN  BODY 


Hair 


6.  State  very  definitely  the  location  of  the  nail  on  a  finger. 
Describe  the  general  shape  of  the  finger  nails,  and  any  mark- 
ings on  them.     What  is  peculiar  in  the  growth  of  the  nails  ? 
What  are  their  uses  ?     What  care  should  be  given  them  ? 

7.  Describe  the  appearance  of  the  skin  in  the  palm  of  the 
hand.     What  variations  are  noted  in  its  thickness?     Ac- 
count   for    the    deep 

markings  in  the  palm 
of  the  hand. 

8.  Name       several 
important  uses  of  the 
hand.       State     what 
difficulties   would    be 
experienced  by  a  per- 
son who  had  lost  both 
hands.       Because    of 
lack    of    hands    how 


Epidermis 


FIG.  2.  —  Cross  section  of  the  skin  greatly 
magnified. 


must  animals  feed  themselves  ?  What  is  true  in  a  general 
way  of  the  adaptation  of  the  hand  for  ministering  to  the 
needs  of  man?  Name  several  uses  of  the  hand  that  il- 
lustrate the  skill  to  which  it  may  attain.  By  what  means 
are  hands  and  fingers  made  to  act  in  obedience  to  the 
mind? 

THE  MOUTH 

1.  In  what  part  of  the  head  is  the  mouth  cavity  ?     Name 
the  walls  by  which  it  is  surrounded.     To  what  else  besides 
the  cavity  is  the  term  mouth  applied  ? 

2.  Describe  the  structure  of  the  lips.     What  is  the  form 
and  size  of  opening  between  the  lips  when  wide  apart  ?     How 


4       LABORATORY  LESSONS  IN  GENERAL  SCIENCE 

much  freedom  of  motion  have  the  lips,  and  how  is  this  se- 
cured ?  Name  the  several  uses  of  the  lips. 

What  can  be  told  of  a  person's  feelings  by  noting  the  lips  ? 
How  may  lip  expression  be  affected  by  an  oft-repeated 
emotion?  Explain  the  redness  of  the  inner  surfaces  of  the 
lips  and  of  their  edges. 

3.  Of  what  use  are  the  cheeks  ?     What  is  their  structure  ? 

4.  Observe  the  rear  wall  of  your  mouth  as  seen  in  a  small 
mirror,  and  describe  what  you  see.     Name  its  various  parts. 

What  is  the  name 
of  the  cavity  farther 
back? 

5.  What    is    the 
character  of  the  roof 
Of       the      mouth  ? 

Wh|ch    WftU    of    the 

nasal  cavity  is  it? 
It  all  the  walls  or 
the  mouth  were  of 

Tongue      ,  .  , 

bone,  in  what  re- 
spects would  its  use- 
fulness be  affected  ? 

6.  Describe   the 
structure,      lining, 
and  general  appear- 

FIG.  3. -The  mouth  cavity.  anCC    °f     the     fl°°r 

of  the  mouth  after 

studying  it  closely  with  the  aid  of  a  mirror.  Note  the 
movements  and  the  structure  of  the  tongue,  and  explain  its 
mobility.  With  the  finger-tips  pressed  against  the  outside 


LESSONS  ON   THE  HUMAN  BODY 


of  the  throat  about  where  the  tongue  seems  to  be  rooted, 
ascertain  if  possible  to  what  it  is  attached.  Of  what  ad- 
vantage is  an  attachment  of  this  kind  ? 

7.  Describe    the    form,    size,    color,    and    coverings   of 
the   tongue.     Note    how    it    may    be   rubbed    against   the 
roof  of   the   mouth,   and  state  what   is   accomplished  by 
this  action  in  eating.     Mention  other  uses  of  the  tongue 
in  eating. 

8.  For  a  person  who  is  in  good  health  what  is  the  ap- 
pearance of  the  tongue  as  to  (a)  moist  look;    (b)  coatings? 
What  information  is  really  sought  by  the  physician  when  he 
"looks  at  the  tongue"?    What  is  tonsillitis  (ton-si-li'tis)  ? 

9.  State   the  location  of  the 
teeth  in  the  mouth  cavity,  and 
their  general  arrangement.     Why 
would  it  not  be  as  well  to  have 
muscle  in  place  of  bone  for  the 
jaws? 

10.  State  the  number,  general 
characteristics,  and  duration  (a)  of 
the  first  set  of  teeth;  (6)   of  the 
permanent  set.     Classify  the  per- 
manent teeth  according  to  form. 
State  the  number,  form  and  special 
use  of  each  of  these  groups. 

11.  Name  the  parts  of  a  tooth. 
Which   part    is    exposed    in    the 
mouth?      What    are   the   gums? 
WThy  should  we  take  good  care  of 
the  teeth  ?     How  often  should  at- 


H«ck 


Bone 

Cement  or  crusta  petrosa 
Alveolar  periosteum  or  root-membrane 


FIG.  4. 


Cross- section  of  a 
tooth. 


6      LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

tention  be  given  them?     What  should  be  done,  and  what 
avoided,  in  order  to  preserve  the  teeth? 

Make  a  study  of  a  tooth  obtained  from  a  dentist,  or  else- 
where, and  tell  the  place  and  nature  of  (a)  dentine;  (b) 
enamel;  (c)  pulp. 

12.  Where   are   the   voice   sounds   produced?     What   is 
the  function  of  the  mouth  in  speech?     What  are  the  bad 
results  of  breathing  through  the  mouth  ?     What  are  ade- 
noids, and  when  may  their  removal  become  necessary? 

13.  Aside  from  its  use  in  speech,  what  is  the  chief  use  of 
the  mouth  ?     What  uses  has  the  saliva  f     By  what  is  its  flow 
affected?    Where  is  it  secreted? 

THE  EYE1 

1.  Describe  the  location  of  your  eyes  with  regard  (a)  to 
the  body  as  a  whole ;   (b)  to  the  face  as  a  whole ;    (c)  to  the 
nose. 

2.  Of  the  eyeball  tell  (a)   its  estimated  diameter;    (b) 
the  general  form  of  it  as  seen  with  the  eyes  widely  opened ; 
(c)  the  names  of  the  several  visible  parts ;  (d)  the  form,  color 
and  relative  position  of  each  part.     In  which  part  of  the 
eyeball  can  changes  in  size  be  noted  ? 

3.  Watch  closely  the  movements  of  the  eyeball,  and  tell 
in  what  directions  it  can  be  made  to  move. 

4.  Make  observations  of  the  eyes  of  several  people  and 
state  what  differences  you  observe  (a)  in  the  depth  to  which 
the  eyes  are  set  in  the  head ;  (6)  in  the  amount  of  ball  exposed ; 

1  Use  a  small  mirror  for  the  study  of  your  own  eye. 


LESSONS   ON    THE   HUMAN   BODY  7 

(c)  in  the  general  appearance,  luster,  expression,  movement 
and  other  characteristics. 

5.  Mention  any  important  purpose  apparently  served 
by  having  the  eyes  placed  (a)  so  high  up  in  the  body;   (6) 
at  the  surface  rather  than  deeply  set. 

6.  What  protection  has  the  eyeball  (a)  at  the    sides; 
(b)  in  front? 

7.  Of  the  eyelids  state  (a)  the  significance  of  the  name ; 
(b)  their  structure;    (c)  the  form  of  each  when  the  eye  is 
closed  and  when  open ;  (d)  their  relative  size ;  (e)  the  amount 
of  motion  for  each ;   (/)  the  place,  of  the  eyelashes. 

8.  Describe  the  nature,  form  and  length  of  the  eye- 
lashes.    What  is  their  apparent  purpose  ? 

9.  State  (a)  what  would  result  if  the  secretion  of  the 
tears  were  to  cease;    (b)  how  the  tear-water  is  spread  over 
the  eyeball ;    (c)  how  much 

of  the  time  the  eyeball  is 
kept  moist ;  (d)  from  what 
point  under  the  lids  the 
tears  flow;  (e)  the  signifi- 
cance of  water  running  from 
the  nose  when  one  cries; 
(/)  why  the  tears  do  not 
overflow  the  cheeks  all  the  FlG'  5"  ~  The  tears' 

time;    (g)  the  course  of  the  tears  across  the  ball. 

10.  When  a  bit  of  dirt  or  any  solid  particle  gets  under  the 
eyelid,  what  may  be  done  to  remove  it  ? 

11.  What  uses  have  the  eyebrows?      In  what  respects 
are  they  unlike  in  different  people  ? 


8       LABORATORY   LESSONS   IN    GENERAL   SCIENCE 

12.  What  defects  of  the  eye  are  common? 

13.  What  care  should  be  taken  of  the  eyes  as  to  (a)  di- 
rection whence  light  comes;    (6)  amount  of  light;    (c)  con- 
tinuous use  of  the  eyes ;   (d)  gen'eral  health  ? 

14.  Discuss  briefly  the  importance  of  sight. 


II.   HEAT  IN  RELATION  TO  THE  HUMAN  BODY 

COMBUSTION 

1.  Put  a  long,  narrow  lamp  chimney  down  over  a  short 
lighted  candle  set  in  a  dish  containing  a  little  water.     Re- 
peat  several   times,   and  state  what  occurs.     Account  for 
the  result. 

Repeat  these  tests,  having  a  partition  of  tin  reaching 
down  through  the  chimney  at  one  side  of  the  burning  candle. 
Hold  an  extinguished  match  that  is  still  smoking  at  the  top 
of  the  chimney,  first  on  one  side  of  the  tin  and  then  on  the 
other,  and  observe  the  smoke.  What  is  the  significance  of 
the  behavior  of  the  smoke  ? 

2.  Let  the  teacher  carefully  melt  a  little  potassium  chlo- 
rate in  a  test  tube,  and  then  heat  it  to  boiling.     Observe  the 
results  as  bits  of  match  sticks  are  dropped  into  the  hot 
liquid.1 

The  gas,  oxygen,  is  set  free  from  the  chlorate  as  result  of 
a  chemical  change,  and  the  union  of  the  oxygen  with  the 
wood  is  another  chemical  change. 

What  is  true  (a)  of  the  nature  of  combustion;  (b)  of  the 
composition  of  air  in  order  that  it  may  support  combustion 
of  the  candle  ? 

1  It  will  be  a  wise  precaution  to  fold  a  strip  of  paper  into  several  thick- 
nesses, and  wrap  it  about  the  upper  end  of  the  test  tube  as  a  holder.  If  the 
tube  be  heated  nearly  its  full  length  at  first,  there  will  be  less  likelihood  of 
breaking  it  when  water  from  the  crystals  of  the  chlorate  is  driven  off. 

9 


10     LABORATORY  LESSONS  IN  GENERAL  SCIENCE 

The  rusting  of  iron  and  the  decay  of  vegetation  are  il- 
lustrations of  oxidation.  Why  are  these  not  commonly  con- 
sidered cases  of  combustion  ? 

3.  Into  an  evaporating  dish  put  a  teaspoonful  of  gasoline. 
Bring  to  it  a  lighted  splinter,  and  observe. 

Half  fill  another  dish  with  kerosene,  and  test  in  like  man- 
ner. Pour  out  all  but  a  little  of  the  kerosene  and  warm 
slowly  what  is  left,  testing  frequently  with  a  lighted  splinter 
held  just  above  the  dish.  What  is  the  nature  of  flame  f 

4.  Light  a  candle.     After  a  moment  extinguish  it,  and 
immediately  hold  a  lighted  match  just  above  the  wick. 
Repeat  several  times,  noting  whether  the  wick  can  be  ig- 
nited when  the  flame  is  some  distance  from  it.     How  is  this 
possible?    What  is  the  "flame"  of  a  candle?    What  con- 
ditions are  necessary  for  any  flame?     Name  in  order  the 
steps  in  the  ignition  and  continued  combustion  of  a  candle. 

5.  Note  the  parts  of  a  candle  flame  distinguished  by  color, 
and  state  their  relation  to  the  wick  and  to  one  another.     Hold 

in  the  candle  flame  just  above  the  wick  the 
wood  part  of  a  match,  withdrawing  it  after 
a  moment  to  observe  the  positions  of  the 
charred  parts  with  reference  to  the  parts  of 
the  flame.  Repeat  several  times,  and  infer 
concerning  the  interior  of  the  flame. 
FIG.  6.  —  Parts  of  Press  down  over  the  candle  flame  nearly 

a  candle  flame. 

to  the  wick  a  sheet  of  white  paper.  With- 
draw it  before  the  paper  ignites,  and  observe  the  form  of 
the  charred  portion.  From  several  such  attempts  reach  a 
conclusion  as  to  the  interior  of  the  flame. 

Describe  the  parts  of  a  candle  flame  as  to  nature  and  form. 


HEAT  IN  RELATION   TO   THE  HUMAN  BODY       11 

Explain  the  persistence  (a)  of  the  inner  cone ;    (6)  of  the 
wick. 

6.  Put  the  tip  of  a  blowpipe  into  the  inner  cone  of  the 
candle  flame,  and  by  repeated  trials  cause  the  yellow  part 
of  the  flame  to  very  nearly  disappear.     What  is  the  explana- 
tion of  this  change  ? 

Hold  the  inner  edge  of  an  evaporating  dish  in  this  blow- 
pipe flame  for  a  moment.  Then  hold  another  part  of  its 
surface  in  the  candle  flarne.  Observe  any  deposit  on  the 
dish  in  either  case,  and  state  its  probable  nature  and  source. 
Account  for  any  variation  in  amount  of  the  deposit  in  the 
two  cases.  Give  an  explanation  of  the  light-giving  power  of 
the  yellow  part  of  the  candle  flame. 

7.  Hold  a  clean  dry  bottle  mouth  down  over  a  burning 
candle,  and  look  for  any  moisture  (water)  on  the  sides  of 
the  bottle.     Assuming  that  there  is  no  water  in  the  candle 
material,  account  for  its  appearance  in  the  bottle. 

Observe  a  lighted  splinter  when  it  is  put"  down  into  the 
bottle  that  has  just  been  held  over  the  candle  flame,  and 
explain  the  results.  Set  the  bottle  aside  with  a  cover  on  it. 
When  it  is  cold  put  into  it  a  little  limewater  (10  c.c.)  and 
shake.  Any  milky  appearance  of  the  limewater  is  due  to 
the  presence  in  the  bottle  of  the  gas  carbon  dioxide. 

8.  Breathe  through  a  glass  tube  into  limewater  in  a  test 
tube  till  a  marked  change  occurs  in  the  appearance  of  the 
limewater.     What  is  the  significance  of  this  change  ?     What 
is  indicated  concerning  processes  within  the  body  ?    Whence 
is  derived  (a)  the  oxygen ;    (6)  the  carbon  ?     In  what  re- 
spects does  this  oxidation  within  the  body  differ  from  or- 
dinary  combustion?     What   significance  has  the  fact  that 


12     LABORATORY  LESSONS  IN  GENERAL  SCIENCE 

people  in  cold  weather  and  in  cold  climates  crave  fatty 
foods?    What  is  the  normal  temperature  of  the  body? 

9.  What  are  signs  of  lack  of  oxygen  in  the  air  that  we 
breathe?  By  what  means  other  than  respiration  may  the 
air  of  our  rooms  be  robbed  of  its  oxygen?  What  provision 
does  nature  make  to  rid  the  air  of  carbon  dioxide  and  restore 
oxygen  to  it  ? 

VENTILATION 

1.  Over  two  holes  cut  in  the  cover  of  an  empty  cigar  box 
set  chimneys  made  air-tight  at  the  bottom  with  vaseline. 
Have  a  bit  of  candle  burning  within  one  of  the  chimneys. 
Test  for  air  currents  at  the  tops  of  the  chimneys  by  means 
of  smoke  from  an  extinguished  match  (or  joss  stick).     Ex- 
plain in  full  what  is  discovered. 

What  is  true  of  the  relative  temperatures  of  the  air  in  the 
two  chimneys?  In  what  other  respects  is  the  air  above 
the  candle  unlike  that  in  the  other  chimney?  How  was 
the  air  in  the  box  affected  because  of  the  differences  in 
temperature  of  the  air  in  the  two  chimneys? 

2.  Why  does  the  air  of  a  schoolroom  need  to  be  continu- 
ously changed?     At  what  season  of  the  year  is  it  neces- 
sary to  give  especial  attention  to  this  matter?    What  eco- 
nomic considerations  are  to  be  taken  into  account  in  the 
ventilation  of  rooms  in  winter?    What  danger  to  health 
must  be  avoided?    What  change  should  the  outside  air  in 
winter  undergo  before  it  is  allowed  to  spread  through  an 
occupied  room  ?    By  what  means  other  than  that  employed 
above  might  a  current  of  air  be  maintained  through  the  rooms 
of  a  building  ? 


HEAT  IN  RELATION   TO   THE  HUMAN  BODY      13 


3.  To  secure  desired  changes  of  air  in  rooms  of  a  build- 
ing provided  with  air-shafts,   but  without  fans  or   other 
devices  for  forcing  air  into  and  out  of  rooms,  what  must 
be  true  at  all  times    (a)   of  the  relative  temperatures  of 
air  at  inlet  and  outlet ;   (6)  of  the  place  for  outlet  that  no 
warmed  air  escape  without  yielding  for  use  its  oxygen; 
(c)    of   the  place  of  inlet   that  the   cold    air    be    warmed 
before  it  spreads  through  the  room?    What  devices  may 
be  employed  to  break  up  an  incoming  cold  air  current  and 
divert  it  upward? 

4.  Hold  a  lighted  candle  (a)  at  the  top  of  an  open  door- 
way;   (b)  down  at  the  floor.     Repeat  the  tests  at  narrow 
openings  made  by  lower- 
ing the  upper  sash  of  a 

window,  and  raising  the 
lower  one.  What  ob- 
jections are  there  to  ven- 
tilating rooms  in  either 
of  these  ways  in  cold 
weather  ? 

5.  Why  is  there  need 
of   special   attention    to 
the    ventilation    of    our 
sleeping   rooms  ?      How 
may   this    be    provided 
even     in     the     coldest 

weather?  What  are  some  of  the  results  of  inattention  to 
ventilation  of  sleeping  rooms?  What  is  the  change  in  com- 
position of  the  air  of  a  room  where  gas  lights  or  oil  stoves 
are  kept  burning? 


FIG.  7.  —  A  victim  of  oxygen  starvation 
becomes  an  easy  prey  for  tuberculosis 
or  other  germ  diseases. 


14     LABORATORY  LESSONS  IN  GENERAL  SCIENCE 


6.  That  the  lungs  may  be  able  to  perform  their  work 
(function)  well,  and  make  use  of  the  available  oxygen,  in 
what  condition  must  the  tissues  of  all  their  parts  be  ?  What 
in  general  are  the  two  requisites  for  the  healthy  condition  of 
any  organ  of  the  body?  Why  is  a  diseased  state  of  the 
lungs  less  likely  in  a  person  who  leads  an  active  out-of-door 
life?  What  is  tuberculosis  of  the  lungs? 

RESPIRATION 

1.  With  the  hands  held  firmly  against  the  chest  walls 
at  the  sides,  take  several  deep  breaths.  Describe  in  a 
general  way  what  motions  of  the  walls  are  noted.  What 
name  is  given  that  part  of  the  breathing  process  in  which 
air  (a)  goes  into  the  lungs ;  (6)  is  expelled  from  the  lungs  ? 

2.  Name  in  order  the  principal  passage- 
ways through  which  air  goes  on  its  way  to 
the  lungs. 

3.  Compare  the  movements  of  air  pass- 
ing into  and  out  of  the  chest  during  respira>- 

tion,  and  into  and 
out  of  an  accordion 
while  being  played. 

4.  Sitting  erect 
and  in  a  comfort- 
able position,  count 
the  number  of  ex- 
halations per  minute 

FIG.  8.  —  Using  a  spirometer  to  test  lung  capacity. 

in  your  breathing. 

5.  Fill  a  gallon  jug  with  water,  and  close  with  a  stopper. 
Let  the  teacher  invert  the  jug,  and  with  its  mouth  under 


HEAT  IN  RELATION   TO   THE  HUMAN  BODY       15 

water  in  a  tub  or  sink  remove  the  stopper.  Holding  the 
inverted  jug  tipped  sufficiently,  let  one  end  of  a  rubber  tube 
be  put  up  through  the  neck  of  the  jug.  Have  some  one 
of  the  class  fill  his  lungs  to  their  utmost  capacity,  and  then 
through  the  tube  force  out  into  the  jug  as  far  as  possible  all 
air  from  the  lungs,  withdrawing  the  end  of  the  tube  from 
the  jug  before  taking  the  other  end  from  the  mouth. 

Keep  the  mouth  of  the  jug  under  water  and  replace  the 
stopper  to  retain  in  the  jug  all  the  water  not  displaced  by 
the  exhaled  air.  Remove  the  jug  from  the  water,  set  it  right 
side  up,  and  by  use  of  a  graduate  ascertain  the  volume  of 
air  expelled  from  the  lungs  by  measuring  the  quantity  of 
water  needed  to  refill  the  jug.1  [Lung  capacity  is  tested 
most  satisfactorily  by  use  of  a  spirometer.] 

6.  In  like  manner,  and  as  average  of  several  trials  by 
the  same  person,  determine  the  volume  of  a  natural  (not 
forced)  exhalation. 

7.  From  the  results  above,  calculate  what  per  cent  of 
the  air  capacity  of  the  lungs  was  used  in  once  breathing. 
Infer  a  good  purpose  served  (a)  by  an  occasional  long,  deep 
breath ;   (6)  by  not  having  the  lungs  emptied  of  all  air  at 
every  breath. 

8.  From  the  data  above  calculate  the  volume  of  air  taken 
into  the  lungs  (a)  per  minute;    (b)  per  hour.      About  one 
fifth  of  this  is  oxygen. 

Calculate  how  long  it  would  take  the  individuals  present 
in  the  room  to  breathe  as  much  air  as  the  room  contains, 
using  the  same  air  but  once. 

1  1000  c.c.  (1  liter)  is  equivalent  to  about  64  cubic  inches. 


16     LABORATORY   LESSONS  IN   GENERAL  SCIENCE 

9.  Close  the  lips  tight,  take  a  deep  breath,  hold  the 
nostrils  tight  shut  with  thumb  and  finger,  and  note  the 
length  of  time  you  can  refrain  from  exhaling. 

10.  Expel  the  air  from  the  lungs  as  fully  as  possible, 
and  note  how  long  you  can  keep  from  inhaling.     Account 
for  its  being  a  shorter  period  than  for  exhaling. 

What  would  be  the  result  of  shutting  off  from  the  lungs 
all  air  supply  for  even  so  short  a  time  as  10  or  15  minutes? 
What  is  the  real  nature  of  death  by  drowning? 

11.  State  so  far  as  known  to  you  the  steps  taken  to  re- 
suscitate (restore  to  life)  a  drowned  person,  together  with 
the  purpose  of  each  step.     What  is  meant  by  asphyxiation 
(as-fik-si-a'shun)  ? 

THE   HUMAN   BODY  AS   AN   ENGINE 

1.  From  a  general  knowledge  of  steam  engines,  state  (a) 
the  purpose  of  burning  fuel  in  the  fire  box;    (6)  the  need  of 
a  draft. 

2.  What  is  true  of  the  relative  amount  of  fuel  needed 
when  the  engine  is  (a)   working  full  capacity,  and  when 
more  or  less  inactive ;   (6)  well  protected  from  the  cold,  and 
when  left  exposed  ?     By  what  means  is  water  changed  into 
steam?     What  then  is  there  in  the  steam  that  does  the 
work  for  which  the  engine  is  employed  ? 

3.  What  will  be  the  effect  (a)  if  the  fuel  supply  is  exhausted ; 
(6)  if  the  draft  is  shut  off  for  any  considerable  time  ? 

What  is  true  of  the  power  of  the  steam  engine  when  there 
is  insufficient  heat?  What  is  the  significance  of  escaping 
steam  when  a  locomotive  is  not  at  work? 


HEAT  IN   RELATION   TO   THE   HUMAN  BODY      17 

4.  Why  may  death  result  if  the  temperature  of  a  per- 
son's body  continues  for  some  time  several  degrees  below 
normal  ?     What  is  evidence  of  a  superabundance  of  energy 
in  a  person? 

5.  What  in  our  bodies  corresponds  to  fuel  for  the  engine  ? 
Name  several  kinds  of  body  fuels.     Before  these  become 
available  as  fuel  what  changes  must  they  undergo  in  the 
body? 

6.  What  part  in  this  heat  production  has  respiration? 
Where  does  the  oxidizing  action  go  on,  and  where  in  the  body 
is  heat  liberated  ?    What  part  in  all  this  has  the  circulation 
of  the  blood? 

7.  Recall  the  effects  of  vigorous  exercise,  whether  of  work 
or  play,  upon  (a)  the  rapidity  and  volume  of  breathing ;  (6) 
the  rate  of  pulse  beat;    (c)  the  temperature  of  body.     Ex- 
plain the  relationship  of  these  conditions. 

8.  How  much  of  our  thought  and  attention  do  the  pro- 
cesses of    digestion,  respiration,   and   circulation   of  blood 
commonly  require?     In  case  we  did  need  to  give  these  ac- 
tivities our  attention,  how  would  it  affect  us  in  the  affairs  of 
life? 

REGULATION   OF   BODY   TEMPERATURE 

1.  Dip  the  hand  into  water;  then  wave  it  back  and  forth 
in  the  air  and  note  the  sensation.  Hasten  the  evaporation 
by  fanning,  and  observe  any  difference  in  the  sensation. 
Whence  is  derived  part  at  least  of  the  heat  necessary  to 
vaporize  the  liquid?  What  is  true  of  the  temperature  of 
the  body  when  perspiration  vaporizes  on  the  skin? 


18     LABORATORY  LESSONS  IN  GENERAL  SCIENCE 

2.  What  is  the  nature  of  perspiration  ?     What  is  meant 
by  a  secretion  ? 

3.  What  relation  is  commonly  noted  between  the  tem- 
perature of  the  body  and  the  amount  of  perspiration  ? 

4.  State  clearly  and  somewhat  in  detail  the  natural  pro- 
vision that  has  been  made  to  avoid  excessive  temperatures 
in  the  body.     What  is  the  apparent  relationship  between 
excess  of  heat  in  the  body,  amount  of  perspiration,  and  the 
disposal  of  this  heat  by  vaporization? 

5.  What  care  should  be  given  the  skin  that  it  may  be 
in  condition  to  regulate  body  temperature?     How  do  we 
protect  the  body  from  sudden  extreme  temperature  changes  ? 
Why  is  there  danger  in  wearing  wet  clothing  ? 

6.  In  what  ways  has  man  provided  against  excessive  loss 
of  body  heat  by  radiation  to  the  surrounding  air?     Why  is 
there  risk  to  health  by  exposure  of  neck  and  chest  in  cold 
weather?      Why    should    a    person    wear   rubbers    in    wet 
weather  ? 

7.  What  is  likely  to  be  true  of  the  temperature  in  any 
organ  or  part  of  the  body  (a)  where  the  blood  vessels  are 
continuously  gorged  with  blood ;    (b)  where  for  any  cause 
excessive  oxidation  is  taking  place?     How  is  the  weight  of 
the  body  affected  by  a  combination  of  excessive  oxidation 
and  impaired  digestion  ? 


III.  HEALTH  AND  WELL-BEING 

KEEPING   WELL 

1.  When   one   is   seriously  sick,  what  are  some  of  the 
usual  expenses  of  the  sickness  ? 

2.  In  a  general  way  what  constitutes  the  difference  be- 
tween being  sick  and  being  well  —  between  having  good 
health  and  being  diseased  ? 

3.  What  may  commonly  be  expected  sooner  or  later  as 
a  result  of  an  unhealthy  or  diseased  condition  of  the  body? 

4.  What  good  purpose  is  served  by  pain?     What  com- 
monly follows  neglect  to  heed  the  first  warnings  of  pain? 

5.  When  a  physician   is   called  in   case  of  any  illness, 
what  will  he  seek  to  discover  before  prescribing  any  treat- 
ment?   Why? 

6.  What  constitutes  the  best  course  for  anyone  to  follow, 
whether  under  direction  of  a  physician  or  not,  as  regards 
air,  food,  drink,  sleep,  exercise?     In  what  respects  other 
than  drink  does  one  need  to  be  "temperate"  ? 

7.  What  is  commonly  true  of  the  body  temperature  as 
a  result  of  serious  illness,  or  of  conditions  in  the  body  likely 
to  cause  sickness?    Why  is  it  well  to  have  for  family  use 
a  thermometer  such  as  physicians  carry? 

8.  In  what  sense  may  it  be  said  that  some  people  culti- 
vate sickness  rather  than  health? 

19 


20     LABORATORY   LESSONS  IN   GENERAL   SCIENCE 


9.  What  effect 
on  the  return  of 
blood  to  the  heart 
has  muscular  exer- 
cise, whether  work 
or  play?  What  in 
the  appearance  of  a 
pers6n  is  evidence 
of  a  sluggish  circu- 
lation? 

10.  Why  is  work 
a  blessing  rather 
than  a  curse  to 

FIG.  9.  —  This  position  makes  impossible  the  full  o      Whpn    HOP^ 

deep  breathing  necessary  for  health. 

it  become  a  curse? 
INFECTION 

1.   It  is  known  that  the  cause  of  many  of  the  diseases 
that  are  "catching"  is  the  introduction  into  the  human  body 

of  living  organisms  so  minute  as  to 

be  seen  only  when  examined  under 

the    microscope.      These    are    very 

properly    called    microorganisms,    or 

microbes,  or  simply  germs.     Many  of 

these  are  minute  forms  of  plant  life 

known  by  the  name  of  bacteria.   Once 

lodged  within  the  body  these  germs, 

under  conditions  favorable  to  their 

growth,  will  multiply  in  number  at  a  truly  marvelous  rate, 

and  directly  or  indirectly  bring  about  a  diseased  condition  in 

the  patient.     What  is  the  meaning  of  the  term  bacteriology  ? 


FIG.  10.  —  Size  of  bacteria 
relative  to  that  of  the 
point  of  a  fine  needle, 
both  greatly  magnified. 


HEALTH   AND    WELL-BEING  21 

The  microscope  is  to  the  bacteriologist  very  much  what 
the  telescope  and  its  accessories  are  to  the  astronomer.  As- 
certain the  literal  meaning  of  the  terms  (a)  microscope ;  (6) 
telescope. 

2.  Fortunately  the  number  of  kinds  of  germs  which  cause 
disease  in  persons  is  relatively  small.     The  symptoms  of 
the  ailment  and  the  degree  of  danger  to  the  life  of  the  patient 
vary  with  the  kind  of  germ,  its  vigor,  and   the   state   of 
health  of  the  person.     In  some  cases  the  development  of 
the  germs  after  their  introduction  into  the  body  can  be 
checked  or  prevented ;    in  other  cases  the  disease  must  run 
a  course  dependent  upon  the  life  changes  through  which 
the  germ  passes.     In  such  cases  whether  the  patient  lives 
or  not  depends  in  large  measure  upon  his  powers  of  endur- 
ance.    Explain  the  weakness  of  body  incident  to  long-con- 
tinued sickness.     Aside  from  feeling  a  need  for  it,  why  is  it 
better  when  sick  to  keep  quiet,  even  remaining  in  bed  ? 

3.  When  persons  recover  from  a  germ  disease  the  sys- 
tem often  seems  to  remain  for  a  considerable  period  of  time 
in  a  condition  unfavorable  to  any  new  development  of  the 
kind  of  germs  that  caused  that  disease.     Ill  effects  may  not 
be  experienced  from  them  for  a  long  time.     One  is  then 
said  to  be  immune  to  that  particular  disease. 

A  like  condition  is  often  brought  about  under  direction  of 
a  physician  by  processes  of  inoculation,  or  vaccination.  There 
is  introduced  into  the  system  a  specially  prepared  virus,  or 
serum.  This  causes  a  mild  form  of  the  ailment,  and  leaves 
the  patient  for  a  time  immune  to  any  severe  attack,  and  pos- 
sibly to  any  attack  at  all  of  that  disease. 

The  life  products  of  the  disease  germs  within  the  human 


22     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 


body  often  act  on  the  tissues  as  poisons,  or  toxins.  They  are 
destructive  of  the  life  of  the  tissues.  Remedies  that  coun- 
teract the  effects  of  these  products,  or  that  prevent  their 
formation  by  preventing  multiplication  of  the  germs,  are 
called  anti-toxins. 

To  secure  immunity  against  what  diseases  are  persons 
vaccinated  ?  For  what  ones  are  serums  administered  ? 

4.  When  the  skin  on  the  body  is  cut  or  torn,  germs 
may  find  lodgment  in  the  wound.  Their  development  and 
multiplication  may  cause  an  unnatural  secretion  called  pus. 
This  pus,  and  the  toxins  it  contains,  when  absorbed  into  the 
blood  and  circulated  throughout  the  system  may  cause 
blood  poisoning.  Aside  from  the  desire  to  relieve  pain 
caused  by  pressure,  why  is  a  physician  or  surgeon  often 

employed  to  lance  any  seri- 
ous swelling,  e.g.,  a  boil? 
Various  substances,  applied 
promptly  to  wounds  and  to 
bandages  used,  either  destroy 
the  germs  or  make  conditions 
unfavorable  to  their  growth 
and  development.  Such  sub- 
stances are  called  antiseptics. 

-Sterilisation  by  boning.       (£^c   hag   reference   to  pu_ 

trefaction  of  animal  tissue.)  Modern  surgery  owes  much  of 
its  success  to  the  use  of  antiseptics.  Where  the  tissues  of  a 
wound  are  kept  free  from  germs  and  in  a  healthy  state, 
rapici  healing  is  possible. 

The  absolute  destruction  of  the  life  of  these  germs,  whether 
by  action  of  chemicals  or  by  high  temperatures,  is  called 
sterilization.  The  surgeon  is  exceedingly  particular  in  all 


HEALTH    AND    WELL-BEING  23 

operations  that  his  instruments,  his  person,  and  his  clothing 
are  sterilized.  . 

"First  aid"  treatment  for  the  wounded,  whether  on  the 
battlefield  or  elsewhere,  seeks  by  the  use  of  antiseptic  treat- 
ments at  once,  and  before  removal  to  any  hospital,  to  pre- 
vent the  infection  of  the  wound,  i.e.,  the  introduction  into 
it  of  germs.  What  is  the  explanation  of  pus  formation  in  a 
wound?  What  in  general  may  be  considered  one  of  the 
chief  functions  of  the  skin? 

5.  In  what  ways    other    than    through  breaks   in  this 
protective  covering  of  the  body  may  germs  be  introduced 
within  the  body?     In  what  several  ways  may  the  presence 
of  the  long-lived  typhoid  germs  be  accounted  for  (a)  in  the 
water  from  wells  and  from  city  water  systems ;   (b)  in  milk 
for  family  use  and  for  sale ;  (c)  in  fruits  purchased  in  market 
and  vegetables  gathered  in  a  home  garden  ?    What  part  are 
flies  believed  to  play  in  the  spread  of  typhoid  ? 

6.  W7here   germs   causing  disease  are  communicated  by 
contact  with  infected  persons  or  their  clothing,  the  disease 
is   spoken   of   as   contagious.      Many    communicable    dis- 
eases may  be  classed  as  both   contagious   and   infectious. 
What  precautions  are  usually  enforced  to  prevent  the  spread 
of  smallpox  and  diphtheria  (dif-the'ri-a)  as  contagious  dis- 
eases?    In  cities  and  towns,  who  has  the  responsibility  and 
the  power  to  enforce  regulations  to  this  end  ?    Why  are 
the  periods  of  quarantine  for  different  contagious  diseases  of 
different  lengths?    What  does  the  physician  do  to  avoid 
carrying  contagious  disease  ? 

7.  In  order  to  avoid  infection  various  means  are  employed 
to  destroy  the  germs  likely  to  be  present  in  the  clothing,  and 


24     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

in  the  waste  matter  of  the  sick  room.  What  exact  meaning 
have  the  words  disinfect  and  disinfection?  What  is  a 
disinfectant?  What  is  the  safest  course  to  pursue  with  re- 
gard to  clothes  used  by  a  sick  person,  and  all  bedding  and 
furnishings  of  small  value?  In  case  infected  clothing  is 
not  destroyed,  how  is  it  to  be  cared  for  until  it  is  washed? 
What  disinfectant  may  be  put  into  the  wash  water?  Why 
should  the  cover  of  the  wash  boiler  be  kept  on  while  the 
clothes  are  being  boiled? 

8.  In  case  a  room  is  to  be  disinfected,  what  kind  of  dis- 
infectants may  be  used  to  insure  the  destruction  of  germs 
lodged  upon  walls  and  furniture,  and  within  blankets,  heavy 
clothing,  and  carpets? 

State  just  how  to  proceed  in  this  disinfecting  process. 
How  much  disinfectant  should  be  used,  and  for  how  long  a 
time? 

9.  How  should  dishes  from  the  sick  room  be  treated? 
How  should  all  waste  matter  from  the  sick  room  be  treated 
before  disposing  of  it  in  sewer  or  cesspool  ? 

10.  What  measures  may  be  taken  for  the  protection  of 
the  public  health  where  through  ignorance  or  carelessness  a 
family  fails  to  observe  proper  precautions?  What  can  be 
done  when  there  is  willful  neglect  by  a  family  to  carry  out 
the  directions  of  the  physician  and  nurse? 

SANITATION 

1.  When  people  are  sick  every  effort  should,  of  course,  be 
made  for  their  complete  recovery.  But  it  is  better  for  them 
as  individuals,  and  better  for  any  community,  to  strive  to 
prevent  sickness  and  disease.  Aside  from  the  suffering  and 


HEALTH   AND    WELL-BEING  25 

hardship  involved,  sickness  is  wasteful.     No  one  can  afford 
it.     About  what  is  the  expense  in  bills  for  doctor,  medi- 


FIG.  12.  —  The  school  doctor. 


cines,  and  nurse  during  a  month's  serious  illness?     Name 
several  other  ways  in  which  there  is  loss  through  sickness. 

Ascertain  the  significance  of  the  terms  sanitary,  sanitation, 
insanitary. 


26     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

Cleanliness  and  wholesomeness  should  characterize  every 
part  in  the  process  of  food  preparation.  Because  it  is  im- 
possible for  consumers  to  know  the  conditions  under  which 
the  foodstuffs  sold  in  market  have  been  prepared,  and 
whether  these  foodstuffs  are  of  the  quality  and  weight 
represented  to  purchasers,  there  has  arisen  need  of  Pure 
Food  Laws  and  of  provisions  for  their  enforcement.  Why 
is  the  need  for  sanitary  precautions  in  handling  food  supplies 
imperative  ?  What  conditions  must  be  observed  in  the  care 
of  food  in  our  homes? 

2.  Explain  why  sleeping  in  small  closed  rooms  in  winter, 
or  working  in  overcrowded  rooms  not  properly  ventilated, 
is  insanitary,  aside  from  the  danger  of  oxygen  starvation. 

3.  Why  is  it  that  open  sewers  and  rotting  piles  of  garbage 
and  stable  refuse  are  insanitary?     What  is  the  common 
means  of  protection  of  our  homes  from  the  flies  that  breed 
in  such  places?     What  is  a  better  course?     Why  is  there  a 
menace  to  health  in  the  exposure  of  foodstuffs  to  dust  blown 
about  on  city  streets?     What  precautions  should  be  taken 
against  infection  with  malarial  germs?     Why  are  not  all 
mosquito  bites  equally  dangerous? 

4.  How  may  ice  become  a  carrier  of  infection?     What 
care  should  be  exercised  (a)  where  food  is  kept  in  refriger- 
ators ;    (b)  in  the  use  of  ice  for  cold  drinks  ?     Why  is  it  that 
food  does  not  spoil  so  soon  when  kept  cold  in  a  refrigerator  ? 

5.  Why  is  there  greater  need  of  attention  to  sanitary 
measures   now   than   formerly?     What   is   the   penalty   of 
carelessness  and  ignorance  in  these  matters  ?     Are  cases  of 
sickness  made  more  dangerous  because  of  a  better  knowledge 
of  the  nature  of  infection?      What  on  the  other  hand  is 


HEALTH   AND    WELL-BEING 


27 


gained  by  reason  of  such  knowledge?  What  results  are 
sought  in  a  widespread  enlightenment  of  people  in  matters  of 
health?  How  many  people  have  need  of  such  knowledge? 
Why  is  it  an  even  greater  need  than  a  knowledge  of  how  to 
cure  illness? 


THE  WATER  SUPPLY  AND  HEALTH 

1.  Account  for  the  supply  of  water  (a)  in  shallow  wells ; 
(b)  in  very  deep  ones.     How  is  the  caving  in  of  dug  wells 
commonly  prevented?     How  is  surface  water  to  be  kept 
from  running  into  such  wells  ?    Why  should  there  be  a  tight- 
fitting  cover  over  the  well? 

2.  Describe  the  general  character  of  the  upper  layers  of 
the  earth's  crust  that  makes  possible  an  ample  water  supply 


FIG.   13.  —  Conditions  for  wells. 

when  pipes  are  driven  through  them.  Illustrate  by  diagram 
the  conditions  that  make  artesian  wells  possible.  How  is 
the  heat  of  certain  springs  and  of  geysers  accounted  for? 

3.  Discuss  the  necessity  for  care  in  locating  wells  near 
dwellings  and  outbuildings.  What  element  of  danger  is 
there  from  cesspools,  drains,  and  leaky  sewers  even  when 


28     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

the  well  is  on  higher  ground?     What  special  dangers  are 
there  in  the  use  of  well  water  in  towns? 

4.  Describe    somewhat    in    detail    the    construction    of 
cisterns.     What  difficulties  are  experienced  in  providing  for 
a  water  supply  by  storage  in  cisterns?     What  advantages 
are  there  in  the  use  of  cistern  water  rather  than  well  water  V 
State  objections  to  its  use  for  drinking  and  cooking.      Aside 
from  the  possibility  of  disease  germs  in  it,  why  may  drink- 
ing cistern  water  cause  sickness? 

5.  By  use  of  a    diagram   show    the    construction    of  a 
cistern  having  a  filtering  wall  of  porous  brick,  and  indicate 
suitable  places  of  inlet  and  outlet  for  the  water.     What 
precautions  should  be  taken  to  keep  cistern  waters  free 
from    dust   and    from    organic   matter?     What   difficulties 
are  there  in  filtering  rainwater  as  it  goes  into  the  cistern? 
What  conditions  in  a  city  usually  make  the  use  of  cisterns 
impossible  ? 

6.  Describe  the  action  of  the  "chain  pump "  as  a  means 
for    aerating    cistern   waters.     Explain  the    nature    of   the 
chemical  change  thus  accomplished  in  the  water.     Account 
for  the  odor  and  taste  of  cistern  water. 

7.  Tell    something    about    an    air-pressure    system    for 
supplying  water  to  all  parts  of  a  house  from  a  cistern. 

8.  State   the  source  of   the  water  supply  of  your  city. 
Describe  the  manner  of  its  storage  and  distribution.     What 
is  the  cost  of  water  to  a  consumer?     What  protection  has 
this  water  supply  from  contamination?    What  means  are 
employed,  if  any,  for  its  purification? 

9.  What  danger  is  there  in  the  use  of  water  from  streams  ? 
What  advantages  may  there  be  ?    What  is  generally  true  of 


HEALTH   AND    WELL-BEING  29 

the  purity  of  spring  waters  ?     By  use  of  a  diagram  show  how 
springs  arise. 

10.  Where  the  water  supply  of  a  city  is  drawn  from  a  river 
into  large  storage  reservoirs,  (a)  what  provision  is  made  for 
filtering  on  a  large  scale  ;   (6)  what  means  other  than  filtering 
is  employed  to  rid  the  water  of  suspended  matter ;   (c)  what 
method  is  employed  on  a  large  scale  for  the  aeration  of 

stored  waters? 

t 

11.  Where  there  is  reason  to  suspect  the  purity  of  a 
water  supply,  what  wise  precaution  should  be  followed  in 
the  home  to  avoid  danger  of  infection  from  the  water  ?     How 
may  it  be  determined  whether  or  not  there  are  "germs" 
in  the  water  supply?     How  is  it  learned  what  particular 
disease  germs  are  present? 

GENERAL  HEALTH  PROBLEMS 

1.  Name  several  conditions  wholly  under  the  control  of 
an  individual  that  contribute  to  the  public  health.     Men- 
tion others,  present  especially 

in  towns,  that  are  not  wholly 
controlled  by  him. 

2.  Describe    in    a    general 
way  how  infection  occurs.     Dis- 
tinguish between  infection  and 
contagion.     What  relation  has 
one's  general  state  of  health  to 
"taking"  a  disease?     What  is 

the    physiological    explanation         FlG.  14.- sunshine  as  a 

Of  this?  disinfectant. 


30     LABORATORY  LESSONS   IN   GENERAL  SCIENCE 


3.  Write  briefly  the  main  features  of  the  life  history  of 
mosquitoes.     What  is  one  way  to  destroy  them  in  great 
numbers,  and  to  keep  rid  of  them  in  an  infested  region? 
What  more  may  be  necessary?     What  part  is  played  by 
one  kind  of  mosquito  in  the  spread  of  yellow  fever  ?     What 
must  be  done  in  order  to  prevent  the  spread  of  this  disease  ? 

4.  Relate    somewhat    at    length  the  life  history  of  the 
common  house  fly.     At  what  rate  do  flies  multiply  under 
favorable  conditions  ?   What  conditions  are  favorable  ?   What 

is  the  procedure  in  a  warfare 
for  their  extermination  ? 

5.  What    is   the   manner   of 
disposal    of    garbage    in     your 
city  ?     In  what  respects  is  there 
menace  to   health    in    such   a 
course  ?     What  better  ways  are 
employed  by  other  cities? 

6.  In  the   installation   of   a 
sewage  system  for  a  town,  wrhat 
must  be  provided  for  moving 

FIG.  15.  —  The  house  fly  (magni-       ,  .    .     . 

fied).    Note  the  hairs  on  legs    the  waste  material  through  the 

and  body.  SCWCrS  ? 

7.  What    is    an    estimated   amount   of   property  losses 
through  the  depredations  of  rats  every  year?     How  are 
buildings  made  rat  proof?     Rats  are  charged  with  being 
agents  in  the  spread  of  the  dreaded  Asiatic  plague.     How 
is  this  believed  to  occur?     What  is  done  to  exterminate 
them  in  a  city  where  the  plague  has  obtained  a  foothold? 

8.  Why  do  we  have  health  ordinances,  and  health  officials  ? 
What  are  the  duties  of  a  Board  of  Health?     Why  is  there 


HEALTH   AND    WELL-BEING  31 

need  of  a  well-informed  citizenship  in  matters  of  public 
health  ?  What  can  the  individual  citizen  do  to  aid  in  main- 
taining public  health? 

9.  Mention  one  or  more  instances  known  to  you  of  the 
enforcement  of  pure  food  laws.  What  are  the  duties  of 
State  Food  Inspectors  generally?  How  may  violations  of 
the  pure  food  laws  be  stopped?  What  are  desirable  health 
regulations  in  the  sale  (a)  of  milk;  (6)  of  fruits  and  vege- 
tables ? 

10.  Explain  the  preservation  of  foodstuffs  (a)  by  employ- 
ment of  low  temperatures,  as  in  cold  storage;  (6)  by  use  of 
high  temperatures,  as  in  sterilization  of  milk  and  in  canning 
foodstuffs;    (c)  by  use  of  , salt,  vinegar,  sugar,  etc.,  in  the 
pickling  processes ;    (d)  by  use  of  smoke  in  the  curing  of 
meats.     Why  then    is    it    considered    so    harmful  to   put 
formaldehyde  in  milk,   boric  acid  in  meats,   and  salicylic 
(sal-i-sil'ik)  acid  in  fruit  products  in  order  to  preserve  them? 

11.  What  are  the  advantages  in  cold  storage  of  perish- 
able foodstuffs?     Why  is  there  need  for  public  control  of 
these  storehouses? 

12.  What  revolution  has  been  wrought  in  the  problem  of 
food  supply  by  the  rise  of  the  canning  industry?    Why  is 
the  control  of  this  industry  in  the  interests  of  public  health 
a  comparatively  easy  problem? 

LIFE,   GROWTH,   REST  AND   RECREATION 

1.  How  can  we  tell  whether  a  tree  is  dead  or  alive  ?  In 
what  ways  can  it  be  decided  whether  an  animal  is  dead  or 
not?  In  general,  how  may  plants  be  distinguished  from 
animals  ?  The  protoplasm  (pro'to-plazm)  of  the  cells  in 


32     LABORATORY   LESSONS  IN   GENERAL   SCIENCE 

plants  and  animals  is  the  material  that  is  alive.  Just  what 
this  "life"  may  be,  making  the  difference  between  living 
and  dead  tissues,  remains  unknown  to  scientists. 

2.  Growth  of  the  tissues  is  commonly  accomplished  by 
the  subdivision  of  living  cells,  apparently  from  causes 
(activities)  wholly  within  the  cell  itself.  These  new  cells 
are  like  the  original  cell,  and  are  in  turn  capable  of  sub- 
division. In  the  case  of  the  microscopic  plants  known  as 


FIG.   16.  —  Successive  stages  in  the  subdivision  of  a  cell. 

bacteria,  subdivision  under  favorable  conditions  is  said  to 
occur  as  frequently  as  every  twenty  or  thirty  minutes. 
Calculate  in  round  numbers  how  many  of  these  one-celled 
bacteria  could  result  in  twenty-four  hours  from  a  single  cell 
where  subdivision  of  every  cell  occurred  every  half  hour. 

3.  In  the  higher  orders  of  plants,  and  in  animals,  the  for- 
mation of  a  more  complex  cell  structure  is  far  slower  than 
this,  and  in  active  animals  like  man  a  fairly  even  balance  is 
maintained  throughout  much  of  one's  life  between  increase 
in  new  cells  and  the  destruction  of  others.     Why  may  any 
considerable  loss  in  weight,  during  middle  life,  or  failure 
during  youth   to   increase   somewhat   regularly   in   weight,' 
be  a  cause  for  concern  ? 

4.  Activity  in  some  form  is  an  accompaniment  as  well  as 
an  evidence  of  life.     A  low  degree  of  physical  or  mental 
activity  is  oftentimes  evidence  of  a  lack  of  sound  conditions 


HEALTH   AND    WELI^-BEING 


33 


of  body.  State  the  relation  of  physical  vigor  (a)  to  an  in- 
sufficient supply  of  nourishing  food;  (6)  to  poor  digestion; 
(c)  to  imperfect  assimilation;  (d)  to  lack  of  pure  air,  suffi- 
cient sleep,  and  suitable  exercise. 

5.    In  what  one  organ  of  the  body  are  largely  centered 
the  activities  upon  which  the  mental  processes  depend  ?     In 


FIG.   17. —  Recreation  at  school. 

general  how  much  does  its  development  depend  upon  mus- 
cular prowess?  Muscular  exercises  and  physical  training 
should  be  directed  chiefly  to  what  ends?  What  is  the  argu- 
ment for  school  athletics  (a)  where  all  pupils  have  opportu- 
nity to  engage  in  them ;  (6)  where  but  a  few  are  trained  whose 


34     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

contests  are  to  be  witnessed  but  not  participated  in  by  the 
school  body  at  large?  What  evils  in  matters  of  health  re- 
sult from  over-training  and  excessive  efforts?  Why  is  it 
that  change  in  occupation  may  afford  refreshment?  How 
is  it  that  activities  employing  both  hand  and  head  are  often 
less  tiresome  than  either  mental  or  manual  labor  alone? 

STIMULANTS   AND   NARCOTICS 

1.  Stimulating     trade,     stimulating     political     interest, 
stimulating  public  opinion,  are  expressions  frequently  heard. 
What  is  there  common  in  their  meaning? 

2.  In  what  ways  may  a  shower  bath,  or  a  sponge  bath, 
have  a  stimulating  effect  upon  the  body?     What  effect  of 
hot  drinks  taken  into  the  stomach  warrants  speaking  of 
them  as  stimulants?     Why  is  the  alcohol  of  various  drinks 
and  medical  preparations  a  stimulant  for  the  human  body  ? 

3.  When   a   horse    is  stimulated  under  vigorous  use  of 
the  whip  to  make  unnatural  efforts  in  moving  heavy  loads, 
what  harm  to  the  animal  is  likely  from  these  efforts  ?     What 
harm  to  the  organs  of  the  human  body  will  probably  result 
from  the  use  of  alcoholic  drinks  even  in  small  quantities? 

4.  What  is  true  of  the  number  of  people  who  begin  the 
use  of  alcoholic  liquors  and  become  addicted  to  the  drink 
habit,  after  they  are  thirty  years  old?     What  significance 
has  this  ?     Why  is  it  that  young  men  beginning  the  use  of 
intoxicating  drinks  are  likely  to  become  drunkards  though 
not  planning  to  do  so? 

5.  Name  some  advantages  to  a  person  in  having  formed 
the  habit  of  doing  what  is  for  his  own  welfare.     What  is 
the  explanation  of  habit  as  a  condition  of  the  body?    In 


HEALTH   AND    WELLr-BEING  35 

what  sense  is  alcoholism  a  disease  ?    Why  do  so  few  recover 
from  it? 

6.  Apart  from  the  use  of  alcoholic  drinks  what  in  general 
constitutes  a  temperate  manner  of  life  ?     What  does  temper- 
ate living  involve  as  to  (a)  kind  and  quantity  of  food  taken ; 
(6)  sleep;    (c)  amusements  and  recreations? 

7.  In  the  building  up  of  the  body  tissues  what  is  the 
food  value  of  tea  and  coffee  ?     In  what  respects  may  their 
use  become  a  serious  menace  to  health? 

8.  What  is  meant  by  narcotics  ?     Name  several.     Under 
what  circumstances  are  narcotics  a  blessing  to  mankind? 
When  do  they  become  a  curse?     Why  are  liquids  contain- 
ing alcohol  included  among  the  narcotics? 

9.  WTiat  is  meant  by  the  drug  habit?     Why  is  it  so 
seldom    overcome?      How    is    it    that    anyone   becomes    a 
victim  of  the  drug  habit  ?     Why  is  instruction  in  the  terrible 
results  of  the  habitual  use  of  drugs  necessary  in  schools? 
Under  whose  direction  only  should  drugs  ever  be  taken? 
Why  so  ?     Why  are  there  such  stringent  regulations  for  the 
sale  of  opium  and  its  compounds,  and  of  other  narcotics  ? 

10.  The  claim  that  one's  nerves  are  soothed  by  use  of 
tobacco  is  confession  of  what  fact?     Give  any  sufficient 
reasons  for  learning  to  smoke  after  one  is  thirty  years  old. 
From  your  knowledge  of  the  growth  of  the  body  by  cell- 
division,  and  of  the  nature  of  the  protoplasm  of  the  cells, 
account  for  the  stunting  of  body  and  mind  in  boys  from  ex- 
cessive use  of  tobacco. 

11.  Why    are    "soothing    sirups"    given     to     infants? 
Judging  from  their  effects  what  must  they  contain?     What 


36     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

is  a  common  constituent  of  them?     What  harmful  effects 
may  follow  their  use  with  infants  ? 

12.  What    alone   constitutes   a   cure   for    any    ailment? 
Wherein  lies  the  efficacy  in  general  of  the  "cures"  for  head- 
ache?    What  is  the  objection  to  an  indiscriminate  use  of 
headache  powders? 

13.  Preliminary  to  all  medical  treatment  worthy  of  the 
name,  and  indispensable  before  administering  any  remedies, 
is  an  understanding  of  the  cause  of  the  ailment  —  a  correct 
diagnosis  of  the  case.     Without  such  knowledge  what  ex- 
pectation can  there  be  that  the  cause  of  the  sickness  will 
be  removed  and  health  restored?     In  the  use  of  "patent 
medicines,"  what  recognition  is  there  of  any  need  to  deter- 
mine the  cause  of  the  ailment  ?     How  much  consideration 
is  given  to  the  manner  of  life  of  the  patient? 

14.  What  is  true   of  the   competency  of  most  people, 
young  or  old,  to  diagnose  ailments  and  prescribe  treatments 
for  themselves  ?     To  what  extent  ordinarily  is  there  any  pro- 
tection to  purchasers  in  having  the  names  of  the  ingredients 
of  any  patent  or  proprietary  medicine  printed  on  the  label  ? 
What  is  true  of  the  knowledge  of  persons  generally  of  the 
effects   of  these   ingredients?     What  explanation   is   there 
for  the  widespread  use  of  patent  medicines  ? 

GENERAL   SCIENCE,   AND   RIGHT   LIVING 

1.  Under  all  normal  conditions  of  living  what  is  true  of 
the  growth  of  children  day  by  day  and  year  by  year  in 
height,  weight,  and  strength?  In  these  respects  at  about 
what  age  does  a  boy  become  a  man? 


HEALTH   AND    WELL-BEING  37 

2.  In  order  to  grow  in  body  day  by  day,  increasing  in 
weight  and  in  strength,  what  are  some  of  the  conditions 
necessary  to   be  observed?     For  intellectual  growth,   and 
for  increase  in  mental  capability,  what  constitutes  (a)  the 
needed  food;    (b)  the  exercise  required?     At  about  what 
ages  does  a  person  attain  full  measure  of  mental  powers? 

3.  It  may  be  assumed  as  true  that  something  more  vital 
than  age  or  stature  marks  the  distinction  between  a  man  and 
a  boy.     The  change  from  childhood  to  manhood  or  woman- 
hood may  very  properly  be  measured  by  an  ability  to  direct 
one's  self  aright  in  what  is  thought  and  said  and  done.     In 
that  case  what  length  of  time  in  a  general  way  is  required 
for  a  child  to  grow  to  be  a  man  or  a  woman  ?     What  are  some 
suitable  tests  to  determine  whether  a  boy  is  growing  to  be  a 
man  or  not  ?     How  much  change  in  this  respect  is  likely  to 
be  noted  in  any  one  day  or  in  several  days  ? 

4.  The  failure  of  a  person  to  do  what  he  knows  should 
be  done  by  him  may  be  considered  evidence  of  what  stage 
of  growth  for  him  ?     What  in  a  large  measure  aids  anyone 
to  decide  whether  any  particular  act  in  life  is  right  or  wrong 
for  him  ?     For  how  many  years  may  one  keep  growing  in  a 
mastery  of  himself  so  that  he  does  what  he  ought,  and  does 
it  without  being  told  to  do  it  ?     If  one  at  all  times  seeks  to 
do  right  things,  how  much  need  will  there  be  for  him  to 
give  attention  to  what  ought  not  to  be  done  ? 


IV.  MATTER  AND  FORCE 

SOME  PROPERTIES  OF  MATTER,  AND  CHANGES  IN 
MATTER  DUE  TO  FORCE 

1.  Into  a  test  tube  already  filled  with  water,  attempt  to 
put  considerably  more  water  without    causing    any   over- 
flow.    What   constitutes   a   satisfactory    "explanation"    of 
the  inability  to  do  this? 

Our  knowledge  of  the  existence  of  the  water,  and  of  the 
existence  of  any  other  portion  of  matter,  involves  the  fact 
that  they  "  occupy  space, "  and  that  no  two  bodies  can  occupy 
the  same  space  at  the  same  time.  To  say  that  matter  is 
that  which  occupies  space  tells  what  matter  is  by  naming  a 
distinguishing  characteristic.  This  does  not  in  any  way 
imply  that  scientists  themselves  have  any  complete  knowl- 
edge of  the  real  nature  of  matter,  nor  does  it  mean  that  there 
may  not  exist  that  which  takes  up  no  room,  and  is  there- 
fore not  matter.  Indeed,  the  study  of  Physics  is  quite  as 
much  concerned  with  that  which  as  force  (the  cause  of  changes 
in  matter)  has  itself  no  material  existence. 

2.  Every  portion  of  matter  extends  outward  from  a  point 
within  the  body  in  three  different  directions,  giving  to  the 
body  its  dimensions  of  length,  breadth,  and  thickness.     Ex- 
tension, impenetrability,  form,  size,  and  density  are  closely 
related    properties    of    matter.      Give   the    definitions    for 
each. 

3.  Push  a  book  lying  upon  the  table,  and  note  that  it 
can  be  moved  —  that  it  has  mobility.     Now  let  it  alone, 

38 


MATTER   AND   FORCE  39 

and  see  if  it  moves  of  itself.  What  is  a  reasonable  inference 
concerning  the  ability  of  a  body  to  move  itself?  When  a 
body  is  found  moving,  what  may  be  assumed  as  cause  of  its 
motion  ?  [In  the  study  of  Physics  phenomena  due  to  any 
"  life  "  in  matter  are  not  considered.  Bodies  are  supposed 
to  be  lifeless.] 

Hold  a  pencil  out  at  arm's  length,  and  then  let  go  of  it. 
When  does  it  stop  falling?  Infer  if  it  could  have  stopped 
itself  when  falling,  all  other  bodies  being  out  of  the  way. 
The  tendency  of  a  body  when  in  motion  to  continue  moving, 
and  the  inability  of  a  body  to  set  itself  in  motion,  constitute 
together  the  characteristic  of  all  matter  known  as  inertia. 
Formulate  a  definition  for  this  property. 

4.  Stretch  a  rubber  eraser ;  then  bend  it,  and  then  twist  it. 
What  holds  the  particles  (molecules)  of  the  eraser  together, 
resisting  their  separation?  Are  the  parts  held  together 
alike  in  nature,  or  unlike?  Define  cohesion.  What  force 
was  applied  in  these  cases  to  change  the  form  of  the  eraser  ? 
Where  a  body  subjected  to  any  force  has  its  form  changed 
rather  than  its  position,  i.e.,  where  it  resists  being  moved, 
it  is  said  to  be  under  strain.  Where  the  body  resists  being 
pulled  apart  it  is  under  tension;  when  twisted,  it  suffers 
torsion;  when  bent,  flexion.  When  the  parts  of  a  body 
are  pressed  together  it  is  said  to  be  under  a  strain  of  com- 
pression. Formulate  definitions  for  these  four  forms  of 
strain. 

The  force  which  causes  any  of  these  forms  of  strain  in  a 
body  is  spoken  of  as  a  stress,  regardless  of  what  force  it  may 
be.  Stress  and  strain  are  thus  correlative  terms,  and  the 
use  of  one  of  them  implies  the  other. 


40    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

5.  When  a  rubber  eraser  is  under  any  strain,  what  marked 
tendency  as  to  form  becomes  at  once  apparent  upon  removal 
of  the  stress?     To  what  is  this  recovery  of  form  to  be  at- 
tributed?    The  property  of  matter  thus  made  manifest  is 
known  as  elasticity.     Formulate  a  definition  for  it,  being 
careful  to  include  mention  of  the  force  upon  which  this 
recovery  of  form  depends. 

Gases  have  no  form  of  their  own,  but  when  released  from 
pressure  they  regain  the  volume  (size)  they  had  before  they 
were  compressed.  Now  re-word  the  definition  for  elasticity 
to  make  it  include  the  more  or  less  complete  recovery  of 
both  size  and  form  in  bodies  when  any  stress  upon  them  is 
removed. 

6.  Try  to  break  a  piece  of  copper  or  iron  wire  by  pulling 
upon  it,  by  bending  it,  and  by  twisting  it.     What  resists 
the   efforts   made?     Say  the  wire  has   tenacity.     In  what 
class  of  bodies  (or  what  state  of  matter)  must  tenacity  be 
lacking?     Define  tenacity  as  a  specific  (not  general)  prop- 
erty of  matter. 


V.   WATER,  AND  ITS  USES 

SOME   PROPERTIES   OF   WATER 

1.  Which  of  all  the  things  needed  to  keep  us  alive  causes 
suffering    most    quickly    when    withheld?     Which    next? 
What  is  the  price  we  need  to  pay  ordinarily  for  either  ?     How 
do  you  account  for  this? 

2.  Taste  water   from  different  glasses,  one  glass  having 
in  it  salt,  another  sugar,  another  vinegar.     Then  taste  of 
pure  water.     What  property  of  pure  water  is  shown? 

3.  Smell  ammonia  water  cautiously;    then  pure  water. 
Name  another  property  of  pure  water. 

4.  Look  at  a  pencil  through  glass.     Put  the  pencil  in 
water,  and  look  at  it  through  water.     What  other  property 
of  water   is   shown?     Explain   the   muddy   appearance   of 
some  rivers. 

5.  Name    several    substances    that    dissolve    readily    in 
water.     Name  a  few  that  do  not.     What  solvent  power  has 
water  as  compared  with  other  liquids?     If  water  did  not 
dissolve  most  substances,  what  would  be  true  (a)  of  the 
digestibility  of  our  foodstuffs;    (6)  of  their  taste?     Name 
some  substances  unsuited  for  food  because  they  are  so  slow 
to  dissolve. 

6.  Pour  water  into  dishes  of  different  shapes,  and  state 
the  form  taken  by  the  water  in  every  case.     Why  is  this? 
Make    a    distinction    between   solid  and   liquid   states  of 
matter. 

41 


42     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

Grasp  a  handful  of  sand.  Try  to  do  the  same  with  water, 
and  explain  the  difference  in  results.  Explain  why  liquids 
at  rest  have  a  smooth  upper  surface  rather  than  a  rough 
heaped-up  form. 

VAPORIZATION   AND   CONDENSATION 

1.  What  change  occurs  in  the  quantity  of  water  (a)  when 
a  little  is  left  in  an  open  dish  exposed  to  the  air  for  some 
time;    (6)  when  a  wet  piece  of  cloth,  as  a  handkerchief,  is 
hung  up  exposed  to  the  air?     After  some  water  has  been 
boiled  for  a  time  in  an  open  dish,  what  is  true  of  the  quan- 
tity of  it? 

In  all  these  cases  what  becomes  of  the  water?  At  what 
temperatures  does  this  change  of  vaporization  of  the  water 
go  on  most  rapidly?  Name  other  conditions  that  favor  a 
rapid  vaporization  of  water  from  the  earth's  surface.  Name 
several  sources  whence  the  supply  of  moisture  in  the  air  is 
maintained.  Whence  comes  the  heat? 

2.  Over  the  mouth  of  a  test  tube  in  which  water  is  boil- 
ing hold  an  inverted  wide-mouthed  bottle  whose  sides  are 
dry  and  cool.     Describe  what  takes  place.     What  relation 
is  there  between  the  processes  of  vaporization  and  con- 
densation?   What    causes    condensation    of    the    moisture 
present  in  the  atmosphere?     In  what  ways  (two  or  more) 
does  this  come  about  ? 

3.  How  is  it  that  in  some  regions  of  earth  a  sudden  and 
extreme  fall   in  temperature  may   cause   no   precipitation 
either  of  rain  or  snow  ?     What  is  true  of  the  general  character 
of  a  region,  and  its  fitness  for  habitation,  where  the  atmos- 
phere is  commonly  destitute  of  moisture  ?     In  regions  that 


WATER,   AND   ITS    USES 


43 


are  far  away  from  large  bodies  of  water,  how  do  you 
account  for  a  supply  of  atmospheric  moisture  sufficient  for 
an  ample  rainfall  ? 

4.  Describe  the  difference 
in  conditions  that  result  in 
the  formation  of  (a)  dew 
and  rain ;  (6)  white  frost  and 
snow;  (c)  fog  and  cloud. 

Why  is  it  that  steam  is 
visible  near  the  mouth  of 
a  teakettle  of  boiling  water  *\G-  18'TGrea,S  cloud  masses  result 


from  the  condensation  to  minute 
water  particles  of  the  water  vapor 
in  ascending  air  currents. 


and  disappears  a  little  far- 
ther outward?  Why  is 
there  no  appearance  of  this  "steam"  close  to  the  outlet? 
5.  When  should  a  gaseous  form  of  matter  be  spoken  of 
as  a  vapor  rather  than  as  a  gas? 


HEAT    OF   VAPORIZATION,    AND    OF    FUSION 

1.  Take  frequent    temperature    readings  as  the  teacher 
heats  some  ice  cold  water  containing  small  lumps  of  ice. 
The  water  must  be  stirred  continuously  with  a  thermometer, 
and  heated  slowly  till  the  ice  is  melted  and  the  water  boils. 
Record  the  temperature  (a)  at  the  beginning ;   (b)  from  time 
to  time  while  the  ice  is  melting;    (c)  during  the  time  until 
the  water  boils ;    (d)  while  the  boiling  water  is  heated  more 
and  more. 

2.  Observe  the  temperature  of  the  room  as  registered 
by  a  thermometer.     Wet  the  bulb  of  the  thermometer  with 
alcohol  (or  water),  and  wave  it  back  and  forth  in  the  air. 
Observe  the  lowest  temperature  it  records. 


44     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

Tie  one  thickness  of  cotton  cloth  about  the  thermometer 
bulb,  wet  it  with  alcohol,  and  repeat  the  test. 

What  becomes  of  the  alcohol  in  both  cases?  Recall  by 
what  means  the  vaporization  of  liquids  has  been  accom- 
plished before.  Give  an  explanation  of  the  thermometer 
changes.  When  vapors  are  condensed  and  changed  to 
liquids  what  is  true  of  this  heat  of  vaporization? 

3.  Into  a  hot  iron  spoon  put  water  a  little  at  a  time, 
and  observe  what  changes  occur  in  the  water  and  in  the  tem- 
perature of  the  spoon.  What  becomes  of  the  heat  that  was 
in  the  metal? 

What  part  does  vaporization  play  in  the  temperature 
of  any  region  intensely  heated  by  the  sun  during  the  day,  as 
during  our  summer  time  ?  What  is  true  of  the  temperature 
of  land  surfaces  largely  destitute  of  water  when  under  a 
summer's  sun? 

SOLUTION,    ABSORPTION,    DIFFUSION 

1.  Make    crayon    marks    on    the    blackboard,    or   lead 
pencil  marks  on  paper.     Why  does  an  attempt  to  jar  or 
shake  these  off  not  succeed? 

2.  Dip  a  finger  into  water.     Explain  why  it  comes  out  wet. 

3.  Let  a  stream  of  water  from  some  height  fall  into  a 
jar  of  water.     Account  for  the  bubbles  of  air  in  the  jar. 

4.  Lower  into  water  a  rough  stone.     Why  do  not  all 
the  air  bubbles  on  the  surface  of  the  stone  rise  to  the  liquid 
surface  ? 

6.  Drop  a  lump  of  salt  into  some  water.  State  what 
change  occurs  in  it.  What  force  that  previously  held  the 
parts  of  the  lump  together  has  now  been  overcome  ?  Where 


WATER,   AND   ITS    USES  45 

is  the  salt  now  ?  Get  a  drop  of  water  from  any  part  of  the 
vessel  that  does  not  have  salt  in  it.  By  what  are  the  particles 
of  salt  and  water  held  together  ?  What  apparently  must  be 
true  of  the  size  of  the  salt  particles  ?  How  is  it  that  every 
drop  of  water  has  apparently  come  into  contact  with  a 
particle  of  salt  without  the  liquid  having  been  stirred  or 
heated? 

6.  Evaporate  some  of  the  salt  solution  to  dryness.     Taste 
any  solid  left.     What  is  it  ?     Let  the  rest  of  the  liquid  stand 
in  a  covered  dish  till  next  day  and  see  if  any  of  the  salt 
settles  to  the  bottom.     If  not,  why  not?     Try  to  filter  out 
the  salt.     What  is  here  taught  of  the  size  of  the  particles? 

7.  Stir  a  little  earth  into  a  tumbler  of  water  and  let  it 
stand.     Explain  what  happens.     Repeat  with  kerosene  and 
water,  and  explain  the  result.     Why  does  cream  rise  on  milk  ? 

8.  Heat  gently  some  water  in  a  test  tube.     Where  does 
the  air  that  collects  on  the  sides  of  the  tube  come  from? 
(Bubbles  of  steam  if  formed  could  not  persist  in  the  water 
below  boiling  temperature.)     Explain  how  this  air  was  kept 
in  the  water. 

9.  Lay  a  blotter  down  upon  a  drop  of  ink.     What  is 
done  to  the  ink  by  the  blotter  ?     How  can  this  be  ?     Since 
we  say  that  water  dissolves  air,  why  not  say  that  the  ink 
dissolved  the   blotter,    or   the   blotter   dissolved   the   ink? 

Give  a  good  definition  for  solution. 

10.  Note  very  carefully  the  results  as  the  teacher  follows 
out  these  directions  :  — 

Wet  the  inside  of  a  clean  bottle  with  .a  little  strong  hy- 
drochloric acid,  and  set  the  bottle  to  drain,  bottom  up.  In 
like  manner  (perhaps  in  another  part  of  the  room)  wet 


46     LABORATORY   LESSONS  IN   GENERAL   SCIENCE 

another  bottle  inside  with  strong  ammonia  water  and  let  it 
drain. 

Both  these  liquids  are  solutions  of  gases  in  water.  The 
bottles  are  thus  made  to  contain  in  one  case  hydrochloric 
acid  gas  and  in  the  other  ammonia  gas.  In  both  cases  these 
are  mixed,  of  course,  with  much  air.  Observe  any  color  or 
other  evidence  of  the  presence  of  the  gases  in  the  bottles. 

When  these  gases  combine  chemically  they  form  particles 
of  a  white  solid  easily  seen.  This  change  can  occur  only 
where  there  is  intimate  contact  of  the  gases. 

Now  bring  the  mouths  of  the  bottles  together,  holding 
both  horizontally.  Note  the  progress  of  the  chemical 
change,  and  explain  the  mixing  of  the  gases  as  the  bottles 
are  held  in  place.1 


OSMOSIS    IN   THE    BODY   AND    IN   PLANTS 

Watch  closely  while  the  teacher  sets  up  the  apparatus  as  directed 
below,  noting  the  results  that  manifest  themselves  through  a  con- 
siderable period  of  time  afterward  :  —  Fill  with 
molasses  a  "diffusion  bulb"  that  has  been 
thoroughly  soaked  for  a  time  in  hot  water,  and 
insert  into  its  mouth  a  close-fitting  rubber  stop- 
per  through  which  has  been  passed  a  rather 
long  glass  tube  of  small  bore.  Twist  a  wire 
tight  around  the  top  of  the  bulb  to  prevent 
any  leakage  around  the  stopper.  Set  the  bulb 
and  its  tube  down  into  a  bottle  of  water  deep 


1  The  striking  change  in  the  substances  here  is 
indeed  a  phenomenon.  In  science  any  change  in 
matter,  however  familiar  it  may  be,  is  considered 
a  phenomenon,  and  is  evidence  of  the  action  of  some 
force.  All  the  changes  of  the  preceding  experiments 
of  this  lesson  are  illustrations  of  phenomena. 


FIG.    19.  —  Osmosis 
apparatus  for  liquids. 


WATER,    AND   ITS    USES  47 

enough  to  cover  the  bulb,  and  let  it  hang  suspended  there  :  till  next 
day  when  the  changes  that  follow  will  come  up  for  discussion. 

1.  Describe  the  change  observed.     What  is  the  explana- 
tion  of   it?     When   liquids   mix    (intermingle)    by   passing 
through   porous    partitions    by   reason   of   their   molecular 
motions  alone,  the  phenomenon  is  known,  as  osmosis.     This 
term  covers  the  mixing  of  gases  in  like  manner.     What 
must  be  true  of  the  freedom  of  molecules  to  move  about, 
that  osmosis,  whether  of  liquids  or  of  gases,  can  occur? 
What  is  done  to  give  solids  the  necessary  molecular  freedom 
for  osmosis?     What  evidence  has  there  been  of  a  greater 
flow  in   one  direction  than   in   the   other?     What   simple 
explanation  for  this  may  be  offered  ?     As  the  liquid  column 
mounts  higher  and  higher,  what  sustains  it  in  the  tube? 
What  measures  the  value  of  this  osmotic  pressure  f 

2.  Some  substances  in  solution  (like  white  of  egg,  and 
solutions  of  starch  and  of  glue)  osmose  but  little  if  at  all. 
Such   substances  have  been   called  colloids,   distinguishing 
them  from  substances  known  as  crystalloids  whose  solutions 
osmose  readily. 

3.  What  condition  of  tissues  is  necessary  that  osmosis 
of  gases  may  take  place   in   the   lungs   whereby   oxygen 
gets  into  the  blood  and  carbon  dioxide  gets  out?     Dis- 
cuss in  detail  this  process  of  interchange  of  gases  in  the 
lungs. 

4.  W7hat  is  the  great  purpose  of  the  various  steps  in  the 
digestion  of  food  ?     What  is  the  chief  end  to  be  attained  in 
cooking  food  ?     WThat  makes  up  the  large  bulk  of  the  diges- 

1  A  rubber  stopper  previously  slipped  on  over  the  upper  end  of  the  glass 
tube  makes  this  suspension  easily  arranged. 


48     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

tive  fluids?     About  what  per  cent  of  the  blood  is  water? 
What  purposes  are  served  by  having  this  so? 

5.  Explain   somewhat  at  length  how  the   various   cells 
of   the  body  get  their  nourishment,  and  how  they  get  rid 
of   their   waste   products.     When   this   waste   matter   gets 
into  the  blood,  how  is  it  disposed  of  ?     Do  the  red  corpuscles 
of  the  blood  pass  through  the  walls  of  the  blood  vessels? 
What  is  true  of  the  white  corpuscles? 

6.  What  part  does  the  solvent  power  of  water  play  in 
the  nourishment  of  plants?     What  part  has  osmosis?     In 
the  growing  plant  evaporation  from  the  leaves  (transpira- 
tion) rids  the  plant  of  relatively  large  volumes  of  its  sap 
water.    What  part  may  this  have  in  the  rise  of  sap  through 
growing  plants? 

STUDY   OF   A   STREAM 

1.  Mention  by  name    (or  locate   otherwise)   the   creek, 
brook,  or  river  nearest  to  the  school   building.     How  far 
is  it  from  the  school  (a)  by  highway;    (b)  by  most  direct 
route  ?    Are  there  fish  in  its  waters  ?  -  If  so,  what  kinds  ? 
If  not,  why  not? 

2.  What  is  true  of  the  rate  of  its  current  at  different 
places?     In  general  is  the  current  swift  or  sluggish?     How 
could  you  determine  quite  accurately  just  how  swift  it  is 
at  any  point?'    Why  is  it  not  swifter?     Account  for  the 
direction  of  its  flow. 

3.  Describe  the  course  of  the  stream  so  far  as  it  is  known 
to  you,  telling  whence  it  comes,  the  general  direction  of 
its  flow,  and  what  becomes  of  its  waters.     Upon  what  does 


WATER,   AND   ITS    USES  49 

the  volume  of  its  waters  depend  ?     For  how  long  a  time  will 
this  stream  naturally  continue  to  flow? 

4.  To  what  distances  up  and  down  have  you  followed  the 
stream  ?     Which  is  the  right  bank  (a)  of  this  stream ;    (b) 
of  any  stream  ?     Describe  in  a  general  way  the  character  of 
country  through  which  it  flows,  whether  hilly,  level,  broken, 
or  mountainous.     Recall   any  relation  between  the   char- 
acter of  the    banks    of   the    stream    and   the   rate    of   its 
current.     What  differences  exist  in  the  bed  of  the  stream 
at  different  places?     How  are  these  accounted  for?     What 
explanation    is    there    for  any  swift  and  broken   current 
("rapids")?     What    significance   have  places  of   compara- 
tively still  water  ?     What  is  true  of  the  widths  of  the  stream 
at  different  points?     What  relation  has  this  to  the  depths 
at  such  places  ? 

5.  Of  how  much  use  in  navigation  is  the  stream?     Why 
so?     Has   it   any  use  for  manufacturing?     Why?     Name 
other  respects  in  which  it  is  of  use. 

VALLEY  FORMATION,   AND   SURFACE   EROSION 

1.  From  observations  you  have  made  of  some  gentle 
slope  (by  field,  roadside,  railway  cut,  or  earth  pile)  where 
the  earth  is  bare  and  subject  to  wash  by  rains,  state  what 
relation  is  apparent  between  steepness  of  slope  and  (a) 
crookedness  of  the  channels  cut  by  the  "flowing  surface 
waters  ;  (b)  depths  of  the  cuts  ?  Offer  an  explanation  (a)  of 
the  crooks  and  turns  in  these  channels ;  (6)  of  the  greater 
depths  of  some  cuts  than  others.  What  is  meant  by  erosion 
(e-ro'zhun)  of  soils? 


50     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

2.  Distinguish   between   a  main   channel,   and   its   trib- 
utaries.    Why  should  there  be  any  tributaries?     What  is 
meant  by  a  divide  between  adjacent  channels  ? 

3.  Make  a  sketch  of  some  imaginary   stream   and   its 
tributaries,    and   by    appropriate    lettering   locate   thereon 
(a)  the  main  channel;    (6)  a  tributary;    (c)  the  mouth  of 
the  main  stream ;   (d)  its  source ;   (e)   a  divide  between  two 


FIG.  20.  —  Canyon  of  the  Colorado  River. 

tributaries.  Inclose  by  a  continuous  dotted  line  on  the 
sketch  what  is  included  in  the  "water-shed"  of  the  system. 
What  is  the  meaning  of  (a)  river  basin;  (6)  river  system? 


WATER,    AND   ITS    USES  51 

4.  How  much  is  included  within  the  limits  of  a  valley? 
How  many  slopes  has  it?     Explain  the  absence  of  streams 
in  so  many  of  the  smaller  valleys  ?     What  various  names  are 
given  to  very  small  valleys  ?     Why  have  these  valleys  never 
become  larger?     Account  for  the  existence  of  valleys  in 
general.     How  may  hills  have  been  formed?     Where  hills 
of  considerable  height  exist  what  is  likely  to  be  true  of  the 
nature  of  the  material  of  which  they  are  made? 

5.  Where  flowing  water  makes  cuts  in  the  earth,   (a) 
upon  what  factors  does  the  rate  of  cutting  depend;    (6) 
which  parts  of  the  surface  are  most  readily  carried  away? 
What  significance  is  there  in  the  muddiness  of  some  surface 
waters  ?     Under  what  conditions  will  this  muddy  water  be- 
come clear  ?     Why  is  it  that  streams  made  up  of  the  surface 
waters  from  the  hillsides  in  some  parts  of  the  country  are 
clear,  and  quite  free  from  sediment?     What  is  the  relation 
of  this  to  the  fertility  of  those  hillsides?     What  becomes  of 
much  of  the  soil  washed  off  into  streams  ?     What  is  the  in- 
evitable result  of  the  continuance  of  this  action  upon  (a)  the 
fertility  of  farm  lands ;   (6)  the  surface  level  of  the  country  ? 


VI.  THE  ATMOSPHERE 

SOME   PROPERTIES   AND   USES   OF   AIR 

1.  Empty  a  filled  bottle  of  water.     What  goes  into  the 
bottle  as  the  water  flows  out? 

2.  Press  a  bottle  mouth  down  into  a  jar  of  water,  and 
over  a  floating  bit  of   cork.     Explain    why  water  fails  to 
enter  and  fill  the  bottle. 

Repeat,  having  an  outlet  through  a  rubber  tube  for.  the 
air  that  is  in  the  bottle. 

3.  By  means  of  a  piece  of  rubber  tubing  attached  to  a 
glass  tube  that  passes  through  the  stopper  of  a  bottle,  force 
into  the  bottle  as  much  air  as  possible,  and  keep  it  there. 

What  must  be  true  of  the  condition  of  the  air  within  the 
bottle  now.  Explain  how  it  is  possible  to  force  more  and 
more  air  into  the  bottle. 

Unclasp  the  delivery  tube  after  putting  its  outer  end  under 
water,  and  observe  what  occurs.  What  must  the  air  particles 
have  done  to  one  another?  Explain  how  it  is  that  water 
vapor  finds  place  for  itself  in  the  atmosphere.  What  prop- 
erty of  air  is  involved? 

4.  Through  a  pipette 1  whose  large  end  reaches  down 
into  water  in  a  tightly  stoppered  bottle,  force  as  much  air 

1  Make  by  heating  a  piece  of  glass  tubing  till  sufficiently  softened  to  be 
easily  drawn  out  into  any  desired  size  when  removed  from  the  gas  flame. 
Allow  it  to  cool,  and  break  tubing  as  desired,  making  use  of  a  sharp-edged 
file. 

52 


THE   ATMOSPHERE  53 

as  possible  from  the  mouth  into  the  bottle.     Withdraw  the 
mouth  quickly  to  one  side.     Explain  the  fountain  effect. 

5.  Where  about  us  is  air  to  be  found?     Attempt  to 
grasp  a  handful  of  it.     Account  for  the  inability  to  do  this. 
Point  to  any  air  that  you  see. 

6.  Look    at    a    pencil    through    window    glass.     What 
property  of  the  glass  is  manifest?     Remove  the  glass,  and 
look  at  the  pencil  through  air.     What  property  of  air  is 
manifest  ? 

7.  What  odor  has  pure  air?     What  taste? 

8.  What    is    a    chief    constituent    of    air   other   than 
oxygen  ? 

9.  Name  several  uses   served   by   air   (a)   when   still ; 
(b)  when  in  motion  as  a  wind. 

10.  Write  in  a  column  a  list  of  a  dozen  things  you  have 
known  the  wind  to  do.     Then  in  a  column,  and  opposite 
every   such   act,   write   adjectives   characterizing   it,   using 
such  words  as  saucy,  tireless,  gentle,  angry,  etc.     Mention 
the  various  names  given  to  winds  by  reason  of  variation  in 
their  force  (intensity). 

11.  What  are  the  names  given  to  winds  according  to 
the    directions   whence   they   blow?     Name   several   ways 
in   which   wind  directions   may   be   somewhat   accurately 
noted. 

12.  Tell  of  the  importance ^of  winds  to  mankind  in  com- 
merce.    In  what  ways  do  winds  minister  to  man's  comfort 
and  to  his  discomfort  ?     In  what  ways  do  winds  affect  man's 
health? 


54    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

PRESSURE   EXERTED   BY   THE   ATMOSPHERE 

1.  Tie  in  loose  folds  some  thin  sheet  rubber  over  the 
large  end  of  a  thistle  tube,  making  air-tight  the  rubber 
covering.     Blow  into  the  open  end  of  the  tube  and  observe 
the  rubber.     Compare  the  amount  of  air  within  the  tube 
now  and  before.     What  must  be  true  of  the  condition  of 
the  air  within  as  compared  with  the  air  without  the  tube? 
Explain  why  the  rubber  is  pressed  outward. 

2.  Using  the  same  apparatus,  suck  some  of  the  air  from 
the  tube  and  observe.     Exhaust  more  of  the  air,  and  ob- 
serve again.     Explain  why  the  rubber  is  now  forced  inward, 
and  why  more  in  one  case  than  in  the  other.     What  relation 
exists  between  the  density  of  the  air  within  the  tube  and  its 
pressure  upon  the  rubber?     With  the  density  of  the  out- 
side air  remaining  the  same,  how  may  the  greatest  inequality 
of  pressure  on  the  sides  of  the.  rubber  be  secured  ? 

3.  Closely  fit  into  a  wide-mouthed  bottle  a  rubber  stopper 
through  which  is  passed  two  glass  tubes,  one  of  them  long, 
and  the  other  short  and  bent  at  right  angles.     Let  the 
longer  tube  extend  down  into  some  water  in  the  bottle. 
Through  the  short  tube  blow  gently  into  the  bottle  and 
observe  the  water  in  the  long  tube.     What  change  in  con- 
dition of  the  air  in  the  bottle  results  from  blowing  more  and 
more  air  in  ?     Why  does  water  rise  in  the  long  tube  ? 

What  relation  exists  between  the  degree  of  compression 
of  the  air  in  the  bottle  and  the  height  of  the  water  column  ? 
What  causes  the  rising  column  to  come  to  rest?  How  long 
will  it  remain  stationary? 

Force  water  up  into  the  long  tube  nearly  to  the  top,  and 
close  the  tube  air-tight  with  one  of  the  fingers,  leaving  a  lit- 


THE   ATMOSPHERE 


55 


tie  air  in  the  upper  end  of  it.  Remove  the  mouth  from  the 
short  tube,  and  observe  the  water  column.  What  is  now 
true  of  the  air  pressures  within  and  without  the  bottle? 
Exhaust  some  of  the  air  from  the  bottle  through  the  short 
tube,  and  observe  the  height  of  the  water  column.  By 
what  is  the  weight  of  the  water  in  the  long  tube  sustained? 

4.1  Fill  with  mercury  a  glass  tube  that  is  at  least  thirty 
inches  long  and  closed  at  one  end.  Holding  the  forefinger 
over  the  open  end,  invert  the  tube 
and  put  this  open  end  down  under 
mercury  in  a  dish  (a  small  mortar) . 
Cautiously  remove  the  finger,  and  ob- 
serve the  upper  end  of  the  mercury 
column.  Explain  why  the  mercury 
column  stands  in  the  tube  above  the 
mercury  level  in  the  dish.  Tip  the 
tube  back  and  forth  sidewise  for  short 
distances,  being  careful  to  keep  the 
lower  end  at  all  times  below  the  sur- 
face of  the  mercury  in  the  dish.  What 
seems  to  be  true  of  the  space  above 
the  mercury  in  the  tube? 

Measure  the  distance  vertically  up- 
ward, both  in  inches  and  in  centimeters,  from  the  surface 
level  of  the  mercury  in  the  dish  to  the  level  in  the  tube. 
How  long  will  this  height  remain  unchanged?  What  is 
true  of  this  difference  in  levels  as  the  tube  is  again  tipped 
sidewise?  As  mercury  is  13.6  times  heavier  than  water, 

1  The  part  of  this  experiment  making  use  of  mercury  should  be  done  by 
the  teacher. 


FIG.  21.  —  A  simple 
barometer. 


56     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

calculate  what  height  of  water  column  would  be  supported 
by  the  same  atmospheric  pressure. 

5.  If  possible  make  a  study  of  a  mercury  barometer,  not- 
ing in  it  (a)  the  mercury  cistern  and  how  the  air  pressure 
from  without  reaches  the  mercury  surface;  (b)  the  heights 
of  the  mercury  column  from  time  to  time,  and  from  what 
point  this  measurement  is  taken  in  all  cases ;  (c)  the  provision 
for  reading  the  height  of  the  mercury  column  to  the  fraction 
of  an  inch. 

What  would  be  the  effect  of  the  presence  of  any  air  within 
the  tube  (a)  upon  a  rising  barometer  column;  (6)  upon  a 
falling  column? 

APPLICATIONS   OF   ATMOSPHERIC   PRESSURE 

1.  Tightly  close  the  mouth  of  a  tall  bottle  with  a  rubber 
stopper  through  which  passes  a  pipette  whose  small  end  is 
inside  the  bottle.     Attach  a  short  piece  of  rubber  tubing  to 
the  large  end  outside  the  bottle,  and  with  the  mouth  by 
repeated  efforts  exhaust  the  air  from  the  bottle,  pinching 
the  tube  together  while  taking  breath.     Put  the  end  of  the 
rubber  tube  under  water,  and  holding  the  bottle  bottom 
up  release  the  pressure  on  the  rubber  tube.     Explain  the 
action  noted.     What  causes  it  to  stop? 

2.  Hold  by  the  bottom  a  tumbler  brimful  of  water.     Press 
down  closely  upon  the  top  of  it  a  piece  of  cardboard,  and 
then  carefully  invert  the  tumbler.     Remove  the  hand  from 
the  cardboard,  and  explain  why  the  water  does  not  fall  out. 

3.  Insert  one  end  of  a  glass  tube  into  water  and  suck  air 
from  the  other  end.     Explain  why  the  water  rises  in  the  tube. 
What  is  a  familiar  application  of  this  principle? 


THE   ATMOSPHERE 


57 


Fill  a  bottle  full  of  water,  and  with  a  rubber  stopper 
carrying  a  long  glass  tube  close  the  bottle  air-tight,  with 
water  in  the  tube  above  the  stopper.  Attempt  to  suck  water 
out  of  the  bottle  through  the  tube,  and  explain  the  results. 
Repeat  the  experiment,  but  with  the  bottle  only  partly 
filled  with  water,  i.e.,  with  some  air  in  the  bottle.  Why  are 
the  results  so  different? 

4.  Follow  very  closely  the  teacher's  explanation  of  the 
action  of  both  lift  pumps  and  force  pumps  as  these  are 
illustrated  by  use  of  glass  models,  or  by  drawings  at  the 
blackboard.     Then  by  the  use  of  draw- 

z> 

ings  on  your  papers  write  brief  descrip- 
tions of  both  kinds  of  pumps. 

5.  From  explanations  of  the  action 
of  air  pumps  by  the  teacher,  based  on 
the  operation  of  an  air  pump   or  on 
drawings  at  the  board,  write  a  descrip- 
tion of  your  OWTL  of  their  construction 
and  operation.     (Use  any  drawings  that 
may  aid   in   making  your  description 
brief  and  clear.) 


6.  Fill  with  water  a  glass  tube  bent 
for  use  as  a  siphon  (si'fon),  one  arm  of 
which  is  only  a  little  longer  than  the 
other.  Holding  a  finger  over  one  end 
so  that  the  water  will  not  run  out  of 
the  tube,  put  the  short  arm  of  the 
siphon  down  into  a  tumbler  filled  with 
water,  and  then  remove  the  finger.  Infer  (a)  what  causes 
the  water  to  rise  in  the  tube  above  the  tumbler  top; 


FIG.  22.  — 
The 

arms  of  the  siphon 
are  from  the  surfaces 
of  the  liquids  at  A 
and  at  D  to  the  high- 
est part  of  the  siphon 


58     LABORATORY   LESSONS   IN   GENERAL   SCIENCE    ' 

(b)  why  the  downward  pull  of  gravity  on  the  water  in  the 
long  arm  is  greater  than  in  the  short  arm ;  (c)  why  water 
in  the  tube  flows  out  of  the  long  arm. 

Repeat  the  experiment,  but  have  the  outer  arm  of  the 
siphon  dip  into  water  that  fills  another  tumbler.  Raise 
and  lower  first  one  of  the  tumblers  and  then  the  other, 
causing  the  water  to  flow  back  and  forth. 

Where  should  measurements  be  taken  to  determine  the 
length  (a)  of  the  short  arm  of  the  siphon;  (6)  of  the  long 
arm? 

7.  From  the  lesson  on  Respiration  recall  and  restate 
how  the  capacity  of  the  chest  cavity  is  increased  and  how 
it  is  diminished  in  natural  breathing.  Explain  why  air 
goes  into  the  lungs,  and  why  it  goes  out,  making  use  of  such 
drawings  of  the  chest  cavity  as  may  be  helpful. 

CAUSES   OF    CHANGE   IN   ATMOSPHERIC   PRESSURE 

1.  Close  a  test  tube  with  a  rubber  stopper,  through  which 
passes  a  glass  tube.     Invert  the  tube  and  hold  the  end  of 
the  glass  tube  under  water.     Heat  the  test  tube,  and  ob- 
serve what  occurs  at  the  mouth  of  the  glass  tube.     Explain 
the  behavior  of  the  air  of  the  tube.     What  is  true  of  the 
density  of  the  remaining  air? 

Allow  the  tube  to  cool  with  the  glass  tube  still  under 
water,  and  account  for  what  occurs.  What  is  true  of  the 
density  of  air  as  it  cools? 

2.  The  weight  of  a  cubic  foot  of  air  and  of  the  vapor  it 
contains  in  grains,  with  the  barometer  at  29  inches,  and 
with  the  temperature  in  Fahrenheit  degrees,  is  approximately 
as  follows :  — 


THE   ATMOSPHERE 


59 


WHEN  SATURATED 

WEIGHT  OF  WATER 

DEGREES  F. 

WHEN  DRY 

WITH  WATER 

VAPOR  IN  1  Cu.  FT. 

VAPOR 

OF  SATURATED  AIR 

0 

604.8 

604.1 

0.553 

32 

564.9 

561.4 

2.128 

62 

532.7 

528.9 

6.167 

102 

494.9 

461.3 

20.979 

In  the  table,  what  is  the  relative  density  (a)  of  dry  air 
and  of  saturated  air  at  the  same  temperatures ;  (6)  of  air 
whether  dry  or  saturated  as  the  temperature  is  increased? 
What  is  true  of  the  amounts  of  water  vapor  held  by  the  air 
as  its  temperature  is  lowered? 

3.  What  must  be  true  of  barometer  readings  (a)  in  a 
warm  moisture-laden  atmosphere;  (b)  in  a  cold  dry  at- 
mosphere ?  With  a  temperature  stationary  or  rising,  what 
is  the  probable  cause  of  a  falling  barometer?  What  is  the 
reasoning  that  forecasts  rainfall  when  there  is  any  consid- 
erable fall  in  the  mercury  column  of  the  barometer? 

CURRENTS  IN  THE  ATMOSPHERE 

1.  In  the  first  paragraph  under 
Ventilation,  what  was  true  of 
the  relative  temperatures  of  the 
air  in  the  two  chimneys  ?  What 
will  the  air  in  the  box  do  because 
of  these  conditions?  Explain 
why  the  air  goes  down  one 
chimney  and  then  on  through 
the  box.  What  is  true  of  the 
temperature  of  the  warmed  air 

FIG.  23.  —  Convection  currents 

after   it    leaves    the    chimney  ?  in  air. 


60     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

Trace  its  possible  course  to  make  a  complete  round  of 
circulation. 

2.  Trace  the  complete  circulation  made  possible  when 
in  one  region  of  the  country  there  is  a  warm  moist  atmos- 
phere, and  in  some  adjoining  section  the  air  is  cold  and  dry. 
How  long  will  this  movement  of  atmosphere  be  maintained  ? 
In  what  part  of  this  circuit  will  the  air  current  be  along  the 
earth's  surface  ?     Where  will  this  air  current  cease  to  exist  ? 
Upon  what  will  the  velocity  of  the  current  largely  depend? 

3.  It  may  be  well  to  distinguish  between  different  parts 
of  this  circulation  of  atmosphere  by  limiting  the  use  of  the 
term  wind  to  the  current  along    the    earth's    surface    as 
distinguished  from  ascending,   descending,   and  upper  air 
currents.     Using  the  term  in  this  way,  infer    (a)    where  a 
"wind"  originates  (springs  up);   (b)  where  it  ends  (ceases 
to  be  a  wind) ;    (c)  from  what  direction  it  will  blow. 

4.  Where   air    currents    are    established,  and    regardless 
of  changes  of  temperature  and  of  moisture,  what  will  be 
the  effect  on  barometer  readings  (a)  of  the  upward  move- 
ment of  the  atmosphere ;  (b)  of  the  downward  movement  ? 

AREAS   OF   HIGH   AND   LOW  PRESSURE; 

1.  In  some  parts  of  the  world  the  sun  at  noon  is  directly 
overhead  —  is  in  the  zenith.     At  what  time  of  year  is  there 
nearest  approach  to  that  condition  here?     What  relation  is 
there  between  the  temperature  of  a  region  and  the  obliquity 
(ob-lik'wi-ti)  of  the  sun's  rays  as  measured  by  the  angle 
between  them  and  vertical  rays? 

2.  That  portion  of  the  earth  where  the  sun's  rays  are 
always  vertical,  reaches  east  and  west  around  the  globe 


THE   ATMOSPHERE  61 

across  northern  South  America,  central  Africa,  and  south- 
ern Asia. 

What  must  be  one  direct  result  of  a  continuous  intense 
heating  of  the  surfaces  of  the  immense  water  areas  of  this 
region  —  the  Torrid  Zone  ?  Name  three  causes  that  com- 
bine to  make  the  barometer  readings  relatively  low  along 
the  line  where  the  sun's  rays  are  all  the  time  vertical  —  the 
so-called  heat  equator. 

3.  As  the  hot  moisture-laden  air  of  the  region  of  the  heat 
equator  ascends,  in  what  directions  other  than  upward  is 
it  likely  to  move  in  the  upper  air  ?     What  change  will  occur 
in  its  temperature  as  it  rises?     What  then  becomes  true 
of  the  amount  of  moisture  this  air  can  hold?     What  is 
true  of  its  density  as  a  result  of  these  changes?     As  this 
upper  air  moves  from  the  equator  poleward,  what  becomes 
true  of  its  elevation  above  the  earth's  surface  ? 

4.  In  moving  northward  from  the  equatorial  region  over 
land  areas  of  varying  altitude,  as  on  the  continent  of  North 
America,  in  what  portion  of  the  continent  are  these  upper  air 
currents  likely  first  to  touch  ground  so  that  moving  along 
the  surface  they  again  become  winds?    What  is  likely  to 
be  true  of  the  character  of  any  such  winds  fed  by  the  descent 
of  upper  air   as  regards   (a)    temperature;    (6)    moisture? 
What  other   direction  than  northward    will   be    taken   by 
this  atmospheric  condition  resulting  from  the  downpour  of 
upper  air  ?     Why  so  ?     What  is  likely  to  be  true  of  the 
barometer  readings  of  the  sections  of  country  over  which  these 
conditions  shall  in  turn  prevail  ? 

5.  With  descending  air  currents  in  any  one  section  of  the 
country,  what  may  reasonably  be  expected  in  some  adjoining 


62     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

section  if  an  equilibrium  of  the  atmosphere  is  to  be  main- 
tained? What  conditions  of  atmosphere  in  any  region  are 
likely  to  favor  the  development  there  of  an  ascending  cur- 
rent? From  how  many  directions  will  winds  blow  toward 
these  areas  of  low  pressure?  At  the  center  of  one  of  these 
areas,  why  is  there  a  "calm,"-  — an  absence  of  all  winds? 
6.  Describe  the  conditions  of  atmospheric  circulation 
exhibited  in  these  diagrams  :  — 

BROKEN  CLOUDS  CIRRUS  CLOUDS 


HEAVY  STRATUS  CLOUDS       'T^TTI-I----  •••.-.•,•.•.-.•..•...•- .•;-?*^— ......        ^        ^  EAST 

DIRECTION 
OF  MOVEMENT 

FIG.  24.  —  The  theoretical  movement  of  air  in  a  "  low." 

Air*.  CIRRUS  CLOUDS 
'.'•Vs    vSiKt  ^  I    FAR         WEATHER 

CLEAR         WEATHER  PARTLY  CCOUDY 


DIRECTION 
OF  MOVEMENT 


FIG.  25.  —  The  theoretical  air  movements  of  a  "high." 


VII.  WEATHER  AND   CLIMATE 

WEATHER   IN   THE   AFFAIRS   OF   MEN 

1.  When  people  talk  about  the  weather  what  are  some  of 
the  comments  usually  made  in  connection  with  (a)  temper- 
ature;    (6)  atmospheric   moisture   and   precipitation;     (c) 
winds ;  (d)  state  of  the  sky ;   (e)  relation  of  weather  to  crops, 
and  trade ;   (/)  effect  on  the  health  and  well-being  of  people 
by  reason  of  weather  conditions? 

2.  What  in  a  general  way  is  the  relation  of  temperature 
(a)  to  latitude ;   (6)  to  altitude ;   (c)  to  situations  far  inland 
as  contrasted  with  nearness  to  oceans? 

3.  Compare  conditions  in  the  very  cold  regions,  the  torrid, 
and  the  temperate,  as  regards  (a)  the  productiveness  of  the 
soil;    (6)  the  working  efficiency  of  man  and  of  domestic 
animals. 

4.  State  any  relation  apparent  to  you  between  the  change- 
able weather  conditions  of  the  temperate  regions  of  the 
earth  and  (a)  the  prosperity  of  their  peoples ;   (6)  the  variety 
in  their  occupations,   skill,  and  productiveness;    (c)   their 
advancement  in  learning,  and  the  stability   of  their  gov- 
ernments. 

5.  In  what  ways  has  the  human  race  sought  to  protect 
itself  against  weather  changes  aside  from  the  kinds  of  food 
eaten?     In  our  modern  civilization  by  what  further  means 
do  we  seek  to  protect  ourselves  (a)  from  extremes  in  tempera- 
ture;   (b)  from  exposure  incident  to  travel  and  out-of-door 
occupations  ? 

63 


64     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

6.  In  what  ways  is  the  manner  of  life  of  a  people  affected 
(a)  by  the  excessive  year-round  heat  of  the  torrid  regions 
of  earth ;    (b)  by  sudden  and  extreme  weather  changes ;   (c) 
by  long-continued  wet  or  dry  periods? 

7.  Of  what  value  to  people  are  weather  forecasts  that  are 
reasonably  accurate?     Upon  what  must  such  predictions 
be  based  to  have  any  especial  worth?     For  about  how  long 
in  advance  can  reliable  forecasts  be  made? 

8.  How  much  is  known  of  the  causes  of  deficient  rainfall 
in  any  region  some  years,  and  of  excess  in  other  years? 
What   control   over   these   conditions   has   man?     Explain 
what  the  mountain  ranges  of  western  United  States  have  to 
do  with  any  semi-arid  conditions  to  the  eastward  of  them. 


FIG.  26.  —  An  irrigation  reservoir. 


WEATHER   AND   CLIMATE  65 

9.  Entirely  apart  from  an  ample  water  supply  what 
must  be  true  of  land  surfaces  to  make  irrigation  for  large 
areas  possible?  Why  is  there  need  of  national  and  state 
aid  in  developing  irrigated  districts?  What  industries 
are  made  possible  in  such  districts?  WThat  .are  the  ad- 
vantages and  what  the  disadvantages  of  living  on  irrigated 
lands? 

10.  Describe  any  extensive  irrigating  system  of  which 
you  have  personal  knowledge,  or  of  which  you  have  acquired 
definite  knowledge  by  reading. 


WEATHER   AS   AFFECTED    BY   HIGHS   AND   LOWS 

1.  From  the  weather  maps  of  Figures  27,  28,  29,1  showing 
the  progress  of  typical  storm  areas,  locate  and  explain  the 
significance  of    (a)  the  isotherms;    (b)  the  isobars;   (c)  the 
wind  directions  from  a  high;    (d)  the  wind  directions  into 
a  low;  (e)  the  modification  of  temperature  of  a  whole  region 
by  an  advancing  high;  (/)  the  isotherms  "running"  with 
the  lows ;   (g)  the  areas  of  precipitation.     Explain  any  pre- 
cipitation in  front  of  an  advancing  high. 

2.  Account  for  wind  directions  at  any  point  not  in  accord 
with  the  general  atmospheric  circulation  about  and  into  a 
low,  or  out  from  a  high.     What  is  the  significance  (a)  of 
the  term  cyclone  when  applied  to  a  low ;  (6)  of  anti-cyclone 
applied  to  a  high?     What  conditions  largely  determine  the 
wind  velocities  reported  at  various  points? 

1  Get  from  the  nearest  Weather  Bureau  Station,  if  possible,  some  daily 
Weather  Maps  of  recent  date.  Ask  that  those  furnished  be  for  successive 
days  during  a  week  or  more. 


66 


67 


WEATHER   AND   CLIMATE 


69 


THE   THERMOMETER 

1.  Close  a  test  tube  filled  with  cold  water  with  a  rubber 
stopper  through  which  passes  a  glass  tube,  and  have  the 
water  stand  above  the  stopper.     Mark  the  water  level  in 
the  glass  tube  by  tying  a  thread  around  the  tube. 

Warm  the  water  in  the  test  tube,  and  observe  the  effect 
as  shown  in  the  glass  tube.     Warm  more 
and  more,  and  observe  further. 

Cool  the  test  tube  more  and  more,  and 
explain  any  changes. 

State  the  general  relationship  apparent 
between  change  in  temperature  and  change 
in  volume.  What  is  meant  by  the  tem- 
perature of  a  body? 

2.  Put  a  chemical   thermometer  having 
both  centigrade   (C.)  and  Fahrenheit    (F.) 
scales  into  water,  and  take  the  readings  of 
the  mercury  level  when  stationary  in  both 
C.  and  F.  degrees.     (Estimate  any  fraction 
of  a  degree  in  either  case  as  tenths  rather 
than  halves,  and  quarters,  and  use  decimals   -ir.s 
rather  than  common  fractions  in  writing 
results.) 

Note  how  many  spaces  of  the  Fahren- 
heit scale  the  0°  F.  is  below  0°  C.  (the  place 

,  -        FIG.  30.  —  Fahren- 

where  the  mercury  level  stands  when  the  heit  and  centi- 
thermometer  is  in  freezing  water).  The 
temperature  of  the  water  is  how  many  F. 
degrees  above  the  zero  of  the  C.  reading?  Calculate  the 
number  of  F.  degrees  (spaces)  to  which  one  C.  degree  of 
the  thermometer  stem  is  equal.  (Carry  the  division  out 


grade    scales    in 
thermometers. 


70     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 


two  decimal  places.)      Note  how  this  compares  with  the 
value  f  (1.8). 

3.  Note  on  each  scale  how  many  degree-spaces  there  are 
between  the  levels  of  the  mercury  when  in  freezing  water, 
and  when  in  boiling  water.     Whence  comes  the  f  used  above  ? 
State  how  to  change  readings  of  centigrade  scale  into  Fahren- 
heit readings,  explaining  why  32°  is  added  to  the  reduction 
value  found. 

4.  State  how  the  Fahrenheit  readings  may  be  changed 
into    centigrade,    and  why  32°   must  now   be    subtracted 
before  the  reduction. 

TEMPERATURE   RECORDS1 

1.  Take  the  temperature  readings  called  for  in  the  blank 
forms  below,  and  record  the  same  at  the  time  taken.  Let 
these  observations  be  made  daily  during  one  week  only  in 
each  succeeding  calendar  month  throughout  the  school  year. 


9:00 

12:00 

1:00 

4:00 

Monday  

o 

0 

0 

0 

Tuesday 

0 

0 

o 

o 

Wednesday  

0 

0 

0 

0 

Thursday 

0 

o 

0 

0 

Friday  

0 

0 

0 

0 

Average  

0 

o 

0 

0 

1  Lessons  requiring  the  keeping  of  records  where  data  are  to  be  gained  by 
observation  through  considerable  periods  of  time  must  be  assigned  suffi- 
ciently long  in  advance.  It  is  unlikely  that  too  great  emphasis  will  be 
placed  upon  the  educational  value  of  sustained  efforts  to  accumulate  and 
classify  facts.  Such  facts  demand  in  themselves  correct  interpretation, 
and  call  for  keenness  of  discrimination  in  relative  values.  There  is  cultivated 
that  desirable  mental  attitude  which  seeks  the  truth  at  every  step,  and  de- 
mands the  facts  before  passing  judgment.  However  important  the  facts 
of  such  lessons,  their  manner  of  acquisition  and  of  use  may  be  of  even 
greater  worth  educationally. 


WEATHER   AND   CLIMATE 


71 


2.  Note  if  the  daily  temperature  changes  appear  to  be 
repeated  over  and  over.  Explain  the  cause  of  such  changes. 
Why  are  the  midday  temperatures  highest  ? 


FIG.  31.  —  Temperature  records. 

3.   Transfer  the  averages  found  above  to  another  tab- 
ulated form,  thus :  — 


9:00 

12:00 

1:00 

4:00 

September 

October 

November  . 

December 

January 

etc  

72     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

4.  At  the  end  of  each  semester,  and  at  the  end  of  the 
school  year,  note  the  seasonal  changes  as  shown  in  the 
twelve  o'clock  averages.  Seek  to  account  for  them. 


SOLAR  HEATING 

1.  Set  the  insolation  apparatus  *  in  a  south  window  and 
so  adjust  it  that  a  beam  of  sunlight,  passing  through  the 
box  and  falling    upon  a    sheet  of    paper   lying  horizontal, 
shows  the  narrowest  outlines  of  the  box  walls. 

2.  Measure  the  area  of  the  paper  covered  by  the  sun- 
beam that  gets  through  the  box,  and  tabulate  the  results  2 
called  for  in  the  form  below  :  — 


DAY 

DATE 

9:00 

(A.M.) 

12:00 
(NOON) 

4:00 

(P.M.) 

OBLIQUITY  3 
AT  12  :  00 
NOON 

TIME  OF 
HIGHEST 
TEMPERATURE 

•OP  DAY 

Monday.  .  . 

.  .  sq.  in. 

.  .sq.  in. 

.  .  sq.  in. 

deg. 

Tuesday.  .  . 

.  .sq.  in. 

.  .sq.  in. 

.  .sq.  in. 

deg. 



Wednesday 

.  .sq.  in. 

.  .sq.  in. 

.  .sq.  in. 

deg. 

Thursday.  . 

.  .  sq.  in. 

.  .sq.  in. 

.  .sq.  in. 

deg. 



Friday  .... 

.  .sq.  in. 

.  .  sq.  in. 

.  .sq.  in. 

deg. 

Average 

1  A  "breakfast  food"  carton  with  both  ends  removed  serves  the  purpose 
well.     To  a  block  of  wood  sufficiently  large  and  heavy  to  serve  as  a  base, 
tack  a  strip  of  wood  for  an  upright ;    to  this  attach  the  carton  in  such  a 
manner  that  it  turns  readily  in  a  vertical  plane.      Turn  the  whole  apparatus 
sidewise,  and  the  carton  up  and  down,  to  get  the  narrowest  possible  shadow 
of  the  walls  of  the  carton. 

2  See  footnote  of  lesson  on  Temperature  Records. 

3  With  a  protractor  measure  the  angle  between   the  edge  of  the  upright 
when  vertical  and  the  upper  edge  of  the  box  as  it  stands  properly  ad- 
justed. 


WEATHER   AND   CLIMATE 


73 


3.  Repeat  these  observations  for  one  week  at  a  time,  and 
at  about  the  same  dates  every  calendar  month  throughout 
a  school  year.  Transfer  the  "averages"  for  each  week  of 
observation  to  a  second  table  as  below.  Only  the  data  by 
months  need  be  preserved  in  the  notebooks. 


MONTH 

9:00 

12:00 

4:00 

OBLIQUITY 

HOTTEST  AT 

September.  .  .  . 
October  
November.  .  .  . 

.  .  .sq.  in. 
.  .  .sq.  in. 
.  .  .sq.  in. 

.  .  .sq.  in. 
.  .  .sq.  in. 
.  .  .sq.  in. 

.  .  .sq.  in. 
.  .  .sq.  in. 
.  .  .sq.  in. 

deg. 
deg. 
deg. 



(etc.,  for  the  whole  school  year.) 


4.   With  practically  the  same  amount  of  heat  (and  light) 
getting  through  the  box  at  different  hours,  what  is  the 


SUN'S  PAYS 

REACHING  EARTH  SUN'S  RAYS  REACHING  EARTH  IN 
AT  NOON  FROM  AFTEROON  WHEN  SUN  IS  LOW  IN 
NEARLY  ABOVE 


SURFACE  OF  THE  EARTH 


FIG.  32.  —  Difference  in  heat  intensity  of  sunlight  at  different  degrees  of 

obliquity. 

relation  between  the  area  covered  by  the  beam  of  sunlight 
and  the  heating  effect  of  that  same  beam  ? 

5.  State  what  is  noted  in  the  monthly  averages  concern- 
ing changes  in  heat  intensity  (a)  through  the  day ;   (6)  from 
month  to  month  by  seasons. 

6.  State  the  relation  apparent  between  obliquity  of  rays 
and  seasonal  changes.    Account  for  this. 


74     LABORATORY   LESSONS  IN   GENERAL   SCIENCE 


M         246        8       10      12      24        68        10      M 

28° 
25f 
24' 
23 
22 

?r 

^20- 
19' 
18 
17" 

x-—  •> 

~V 

/ 

~^x 

^ 

7 

">• 

N 

/ 

\ 

/ 

\ 

^v 

/ 

x 

*^_ 

/ 

FEB.  19,1893  ITHACA 

FIG.  33.  —  Range  in  temperature  dur- 
ing twenty-four  hours. 


7.  Attempt  an  explana- 
tion of  the  fact  that  the 
highest  temperature  of  the 
day  comes  later  than  noon, 
which  is  the  time  of  great- 
est solar  heating.1 

8.  Why  is  it  warmer  at 
sunset  than  at  sunrise  ? 


9.  Why  is  it  that  in 
northern  latitudes  the 
coldest  weather  is  likely 
to  be  in  January  and 
February  rather  than  in 
December  ? 


FEB.    MAR.   APR.     MAY    JUNE    JUL*    AUG.  SEPT    OC 


X 


,-o-qgdfe^^i:--^ 
>-"o?(         _  ^^ 


2. 


x 


x 


FIG.  34.  —  Range  of  temperature  during  a 
year  for  five  places  having  very  differ- 
ent climatic  conditions.  The  influence  of 
the  oceanic  waters  of  the  Tropics  is  seen 
in  4  and  5. 


1  It  may  be  possible  to  make  more  clear  the  cumulative  heating  by  day, 
and  throughout  a  summer,  by  use  of  several  dishes  of  different  capacity 
and  a  vessel  of  water.  The  gain  and  the  loss  of  heat  per  hour  at  the  place 
where  the  observer  is  stationed  on  the  earth  may  be  represented  by  quanti- 
ties of  water  added  to  or  taken  from  an  original  volume  in  the  vessel.  The 
hourly  losses  by  radiation  from  the  earth  through  a  24-hour  period  may  be 
considered  as  approximately  the  same'  for  any  observer.  The  gain  in  heat 
per  hour  increases  up  to  noon,  and  then  decreases,  although  for  some  time 
after  the  noon  hour  the  gai^n  per  hour  exceeds  the  loss. 


WEATHER  AND   CLIMATE 


75 


GENERAL  WEATHER   RECORD  1 

1.    As  assigned  by  the  teacher,  collect  and  tabulate  the 
data  called  for  below :  — 


DATE 

TEMPERA- 
TURE 

PRESSURE 
(NOTE  1) 

WIND 

DIRECTION 
(NOTE  2) 

AMOUNT  op 
PRECIPITATION 
(NOTE  3) 

STATE  OP 
SKY  2 

o 

in. 

in. 

0 

in. 

in. 

0 

in. 

in. 

o 

in. 

in. 

0 

in. 

in. 

Average 

o 

in. 

(Prevailing 

(Total) 

(Number  of 

wind) 

clear  days) 

2.  From  the  data  gathered  above,  and  from  the  tabulated 
averages  and  totals,  seek  to  discover :  - 

((a)  The  prevailing  wind  characteristic  of  any  season. 

(6)  The  relative  amount  of  precipitation  by  months  and 
by  seasons. 

(c)  Any  seasonal  round  of  clear  and  stormy  weather. 

(d)  The  temperature  ranges  and  averages  for  the  differ- 
ent seasons. 

1  See  footnote  of  lesson  on  Temperature  Records. 

2  By  use  of  a  circle  (O),  a  clear,  partly  cloudy,  or  overcast  sky  may  be 
shown  by  the  degree  of  shading;   an  inclosed  R  =  rain,  and  an  S  =  snow. 

Note  1.  Some  one  in  the  community  may  have  a  barometer  from  which 
readings  can  be  taken  in  case  the  school  does  not  possess  its  own  instrument. 
If  necessary,  omit  the  pressure  readings,  as  well  as  (/)  and  (h). 

Note  2.  A  sufficiently  good  weather  vane  may  be  made  and  mounted  on 
the  schoolhouse  by  any  local  mechanic,  or  by  one  of  the  older  pupils. 

Note  3.  Where  a  rain-gauge  (gaj)  is  not  available,  a  tin  can  with  straight 
sides  (such  as  a  large-size  baking-powder  can)  may  be  set  into  a  light  frame- 
work to  keep  it  from  being  blown  away.  Put  the  can  out  in  the  open  away 
from  trees  and  buildings.  Using  a  foot  rule  graduated  to  16ths  of  an  inch, 
measure  the  depth  of  water  in  the  can,  always  holding  the  rule  vertical. 


76     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

(e)  Any  apparent  relation  between  wind  direction,  tem- 
perature, and  rainfall. 

(/)  The  relation  of  barometric  fluctuations  to  weather 
changes. 

(g)  Any  relation  between  wind  direction  and  state  of  the 
sky. 

(h)  Temperature  and  barometric  changes  during  the  pass- 
ing of  a  low. 

3.  From  the  data  accumulated  at  the  various  Weather 
Bureau  Stations  since  the  establishment  of  the  U.  S.  Weather 
Service  in  1870,  state  what  appears  to  be  true  of :  - 

(a)  Any  relation  between  the  weather  and  "  changes  in 
the  moon,"  i.e.,  changes  in  its  phases. 

(6)  Accuracy  in  any  detailed  weather  forecasts  for  a  year 
ahead. 

(c)  The  recurrence  of  approximately  the  same  changes  of 
weather  for  recurring  seasons. 


VIII.  AT  OUR  HOMES1 

ROOMS  OF  THE  HOUSE,  AND  THEIR  FURNISHINGS 

(a)   The  Kitchen 

1.  What  is  the  relative  use  of  the  kitchen  and  of  the  other 
rooms  of  the  house  during  the  day  ?     Why  is  it  best  not  to 
have  the  kitchen  a  large  room  ?     What  is  a  good  size  for  it  ? 
Using  a  scale  of  £  inch  =  one  foot,  represent  on  your  paper 
a  desirable  size  and  form  for  a  kitchen. 

2.  Name  some  of  the  kinds  of  work  carried  on  in  a  kitchen 
in  connection  with  the  weekly  routine  of  household  duties. 

3.  State  what  economies  are  possible  in  the  purchase  and 
storage  of  coal  for  household  use.     Name  various  kinds  of 
coal,  and  tell  their  relative  fuel  values.     What  special  care 
should  be  given  the  kitchen  coal  stove  (or  range)  ?    What 
may  be  done  to  keep  fire  overnight  in  it  ?      Tell  how  to  build 
a  fire  in  the  stove  (or  range),  and  how  to  avoid  waste  of  coal 
in  the  ashes. 

4.  About  what  is  the  cost  of  a  gas  (or  gasoline)  range? 
What  is  the  cost  of  gas  (or  of  gasoline)  ?     In  what  ways  may 
there  be  waste  in  the  use  of  gas  in  the  kitchen  ?     Explain  the 

1  While  much  that  is  required  in  these  lessons  on  the  home  may  be  matter 
of  common  knowledge  to  the  pupils  generally,  it  is  nevertheless  urged  that 
there  be  considerable  discussion  in  detail  of  household  economies  and 
household  management.  However,  any  mere  statement  of  the  facts  re- 
quired by  these  lessons  is  far  less  important  than  the  establishment  of  whole- 
some ideals  of  a  simple  manner  of  living,  and  a  realization  of  the  possibil- 
ities of  a  modern  American  home. 

77 


78     LABORATORY   LESSONS  IN   GENERAL   SCIENCE 

economy  of  a  fireless  cooker  where  gas  is  used  for  fuel. 
Name  several  advantages  in  the  use  for  fuel  (a)  of  coal; 
(6)  of  gas. 

5.  Of  the  kitchen  sink  tell  (a)  the  kind  and  size  desirable, 
and  its  cost;  (6)  the  purpose  of  a  trap  for  it;  (c)  how  to 
keep  the  waste  pipe  from  becoming  clogged,  and  how  to  clean 


FIG.  35.  —  Kitchen  furnishings. 

it  from  time  to  time.  What  is  the  cost  of  water  in  your  town 
for  household  uses?  What  are  some  advantages  in  the  use 
of -cistern  water?  Name  some  conveniences  to  be  kept  at 
or  near  the  sink.  Why  is  it  better  to  have  open  plumbing 
(pipes  exposed)  than  to  have  the  pipes  inside  partitions  or 
cupboards  ? 


AT   OUR   HOMES 


79 


6.  About  what  is  the  cost  of  a  kitchen  table  (or  kitchen 
cabinet)  ?     What  conveniences  should  the  table  (or  cabinet) 
provide  ?     What  kind  of  a  top  should  the  kitchen  table  have  ? 

7.  What  need  is  there  of  doors  for  kitchen  cupboards? 
Give  a  list  of  the  dishes  and  utensils  likely  to  be  kept  in  a 
kitchen  cupboard. 

8.  What  are  the  objections  to  a  soft  wood  floor  for  the 
kitchen  ?    Why  not  have  painted  floors  ?    What  care  should 
be  given  oiled  hard- 
wood   floors  ?     State 

objections  to  having 
any  floor  covering. 
What  is  the  cost  of 
linoleum?  What 
should  be  done  from 
time  to  time  to  keep 
the  linoleum  imper- 
vious to  water  ? 

9.  What  are  va- 
rious     finishes      for 
kitchen  walls?     Dis- 
cuss   their     relative 
cost,  and  their  other 


FIG.  36.  —  Food  may  be  kept  in  a  box  just 
outside  the  pantry  window. 

Why  remove 


merits  ? 

10.  Why      should 

there   be   screens  at  the  kitchen  windows? 
and  store  the  screens  during  the  winter  ? 

11.  What  are  the  advantages  in  having  a  separate  room 
for  a  kitchen  pantry?    Why  have  cupboards  in  it?    Why 
have  a  window? 


80     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

12.  Name  several  considerations  that  influence  the  choice 
of  a  position  for  the  refrigerator  for  household  uses.     State 
the  special  care  that  should  be  given  it. 

13.  Make  a  floor  plan,  drawn  to  a  scale,  showing  the  re- 
lation of  the  kitchen  to  (a)  back  yard  and  back  porch; 
(6)  basement;    (c)  dining  room;    (d)  pantry.     (Make  the 
arrangement  of  rooms  such  that  the  paths  most  frequently 
traveled  to  and  from  the  kitchen  range  shall  be  the  shortest 
distances.) 

(b)   The  Dining  Room 

1.  What  is  a  usual  size  and  form  for  the  dining  room  ? 
What  furnishings  are  needed  for  it  ?    What  is  a  satisfactory 
floor  covering  for  the  dining  room  ? 

2.  Discuss  (a)  the  dining  room  table  —  its  material,  cost, 
and  the  proper  care  of  it ;   (6)  the  kind  and  cost  of  dining 
room   chairs;    (c)  the  need  of   a  sideboard,  and  itf  cost; 
(d)  the  advantages  of  a  "built-in"  china  closet. 

3.  When  the  breakfast  table  is  "set"  for  five,  (a)  what 
are  suitable  dishes  and  tableware,  and  how  are  these  to  be 
arranged?     Name  some  foods  ("dishes")   for  a  balanced 
"two-course  dinner." 

4.  What  care  should  be  given  the  dining  room  daily? 
What  objections  are  there  to  eating  in  the  kitchen? 

(c)  Bathroom 

1.  Where  with  reference  to  other  rooms  may  the  bathroom 
be  (a)  in  a  one-story  house;  (6)  in  a  two-story  house? 
What  kind  of  wall  is  desirable?  How  may  hot  water  be 
provided  for  the  bathroom  ? 


81 


82     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 


FIG.  38.  —  Furnishings  of  a  bathroom. 

(d)  Sleeping  Rooms 

1.  Where  usually  are  the  sleeping  rooms  in  a  house  ?  Why 
may  it  be  desirable  to  have  a  sleeping  room  downstairs? 
What  is  a  good  size  for  a  sleeping  room  ?  What  furniture  is 
desirable  other  than  bed,  couch,  or  cot  ?  Mention  desirable 
conditions  as  to  (a)  windows ;  (6)  closets ;  (c)  floor  covering. 

(e)  Living  Room 

1.  What  is  the  advantage  of  a  hall  or  vestibule  leading  into 
the  general  living  room  ?  Discuss  the  cost,  construction,  and 
size  of  a  desirable  kind  of  library  table,  and  various  provisions 
for  artificial  light  to  use  with  it.  Describe  some  desirable 


AT   OUR    HOMES 


83 


Hot  vSafe 


kinds  of  bookcases,  and  make  a  list  of  some  good  books  for 
the  home  bookcase.  Make  a  list  of  other  furnishings,  such 
as  chairs,  rugs,  etc.,  and  give  their  probable  cost. 

(f)  Basement 

1.  To  what  use  is  a  basement  commonly  put?     What  is 
its  value  in  the  matters  of  health,  and  of  warmth  for  the 
rooms  above?     How  may  it  be  made  rat-proof? 

2.  Name  several  kinds  of  heating  plants.     So  far  as  pos- 
sible   tell    something 

definite  (a)  of  their 
relative  cost;  (6)  of 
their  period  of  use- 
fulness; (c)  of  their 
expense  of  mainte- 
nance. Why  is  there 
need  of  a  separate 
room  for  coal  ?  How 
may  the  dust  be  les- 
sened when  coal  is 
handled? 

3.  Why  is   it  well 
to  have  the  laundry  in 
the  basement?   Name 
desirable    furnishings 
and  conveniences  for 

it.  What  other  place  may  there  be  in  the  house  for  drying 
clothes  indoors  in  stormy  weather  ? 

4.  Copy  the  diagram  given,  and  by  use  of  arrows  show 
how  from  a  "  water-front "  in  the  kitchen  range  hot  water  may 


FIG.  39.  —  Hot  water  from  the  kitchen  range. 


84     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

be  provided  for  the  kitchen  sink,  a  bathroom  upstairs,  and 
a  laundry  in  the  basement. 

5.  Make  a  diagram  showing  a  hot  water  plant  in  the  base- 
ment, with  radiators  for  one  room  each  on  the  first  and  second 
floors,  and  an  overflow  tank.  What  special  care  is  necessary 
in  the  location  of  pipes,  and  in  plans  for  their  drainage  ? 

THE   COST   OF   LIVING 

(a)  Food 

1.  About  what  is  the  cost  of  cereals  (se're-als)  per  pack- 
age ?     This  is  about  how  much  per  pound  ?     Tell  the  manner 
of  cooking  and  serving  them.     What  is  the  economy  (a)  of 
buying  them  in  bulk ;  (6)  of  cooking  them  with  a  fire  in  use  for 
other  purposes?     What  range  of  choice  is  there  in  "break- 
fast foods"?     Why  is  it  wise  to  make  use  of  different  kinds 
of  grains  from  time  to  time?     How  do  the  nutritive  values 
of  the  cereals  compare  with  one  another  and  with  meat  ? 

2.  About  what  is  the  cost  of  eggs  in  summer  and  in 
winter?    How  is  the  storage  of  eggs  in  quantity  at  home 
accomplished  ? 

3.  About  what  is  the  cost  of  coffee  per  pound  ?    What  is 
the  manner  of  its  preparation  for  table  use?     About  how 
many  cups  of  drink  are  made  from  a  pound  of  it?     What 
limitations  in  its  use  as  a  drink  should  be  observed  by  adults 
and  by  children  ? 

4.  What    are   desirable  foods  for  breakfast?     What  is 
true  of  the  nutritive  value  of  fruits?    \Vhat  are  reasons 
other  than   cost   for   not   having   meat   and  potatoes   for 
breakfast  ? 


AT   OUR   HOMES 


85 


CARBOHYDRATES  THE  HEAVY  BLACK  LINES  IN  THE  CHART  BE- 
LOW INDICATE  THE  RELATIVE  FUEL  VALUE 
IN  ONE  POUND  OF  EACH  OF  THE  NUTRIENTS 


SALT  PORK,  VERY  FAT 


WEIGHTS  OF  NUTRIENTS  AND  FUEL  VALUE 
IN  25  CENTS'  WORTH. 


CODFISH,  FRESH 
CODFISH, SALT 


3.13 

3.57 


ii 


MACKEREL, SALT 


OYSTERS,  35  CTS.  QUART 


EGGS,  25  CENTS  DOZEN 


MILK,7  CENTS  QUART 


mwm 


CHEE8E, WHOLE  MILK 
CHEESE, SKIM  MILK 


FIG.  40.  —  The  relative  values  of  foodstuffs. 


86      LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

5.  About  what  is  the  usual  cost  of  potatoes,    fall  and 
spring  ?     What  are  necessary  conditions  for  their  storage  in 
quantity  in  the  home?     Name  ways  of  preparing  them  for 
table  use  (a)  for  the  sake  of  variety;    (6)  for  purposes  of 
economy ;   (c)  with  reference  to  the  season. 

6.  What  are  the  prevailing  prices  of  different  cuts  of 
beefsteak  ?     What  are  their  relative  nutritive  values  ?     How 
should  steak  be  cooked,  and  why  so  ?     What  is  the  relative 
cost  of  steak,  and  of  meat  for  boiling  ?    What  is  their  relative 
value  as  foods?     What  cooking  procedure  in  the  boiling  of 
meat  gives  best  results  ?     What  management  will  save  fuel  ? 
What  is  the  manner  of  preparation  of  soup,  and  what  is  its 
food  value? 

7.  About  what  is  the  cost  of  butter  per  pound,  and  of 
bread  per  loaf?     What  economies  are  possible  in  the  use  of 
butter?     Discuss  substitutes  for  butter  in  cooking  —  their 
food  value,  and  their  wholesomeness. 

8.  Give  the  cost  of  various  kinds  of  garden  stuff  in  sea- 
son, —  as    corn,    peas,    string   beans,    asparagus,    rhubarb, 
beets,    tomatoes,    radish,    lettuce,    cabbage.     What    table 
variety  may  be  had  in  canned  vegetables?     What  is  their 
usual  cost  per  can  ?     WThat  is  the  relative  nutritive  value  of 
canned  and  fresh  vegetables?     Discuss  the  relative  cost  of 
home  canned  goods  and  the  factory  product. 

9.  Name  various  forms  of  dessert  in  common  use,  and 
give  their  relative  cost. 

10.   Mention  the  various  dishes  in  common  use  for  sup- 
per, their  relative  cost,  and  their  wholesomeness. 


AT   OUR   HOMES  87 

(b)  Clothing 

1.  Name  the  two  chief  economic  ends  in  view  in  the  pur- 
chase of  clothing.     By  what  is  one  to  be  guided  in  judgment 
as  to  (a)  real  values  in  clothing ;  (b)  wearing  quality  ?    What 
general  rule  is  to  be  followed  in  making  purchases  because 
articles  are  "cheap"?     What  advantage  is  there  in  buying 
from  reputable  firms  with  well-established  business  standing  ? 

2.  What  is  true  of  the  cost  of  the  same  articles  (as  of  suits 
and  millinery)  "in  season"  and  "out  of  season"?     What 
differences  in  the  cost  of  clothing  for  the  year  may  result 

(a)  from  purchases  at  favorable  times ;   (b)  from  wise  selec- 
tions as  to  service  ? 

3.  Discuss  the  extent  of  economies  possible  through  the 
making  of  garments  at  home.     What  is  the  value  in  the  home 
of  a  knowledge  (a)  of  dressmaking ;  (6)  of  millinery  ?     How, 
where,  and  when  is  this  knowledge  to  be  gained  ? 

4.  Discuss  extravagances  (a)  from  extremes  in  fashion; 

(b)  from  choice  of  what  is  not  suited  to  intended  uses; 

(c)  from  lack  of  care  in  wearing,  or  in  storage. 

5.  Make  lists  (several  items  each)  of  articles  that  belong 
in  the  class  (a)  of  things  which  must  be  provided  for  com- 
fort and  well-being;    (6)  of  luxuries,  whether  wholesome  in 
influence  or  not. 

6.  What  constitutes  a  good  standard  in  dress  for  anyone 
to  follow?     To  what  extent  shall  fashion   (the  prevailing 
mode)  be  followed  by  anyone  ? 

(c)  Rents 

1.  Name  many  advantages  from  ownership' of  one's  home. 

2.  What  items  are  to  be  calculated  in  the  cost  of  owning 


88     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

one's  home  in  addition  to  (a)  interest  on  sum  invested; 
(b)  insurance;  (c)  repairs  (on  an  average)  every  year; 
(d)  taxes ;  (e)  depreciation  in  property  through  use  ? 

3.    Name  the  several  factors  entering  into  a  calculation  of 
rental  values. 

(d)  Other  Items  in  the  Cost  of  Living 
1.   Name  various  furnishings  of  homes  not  before  men- 
tioned. 


FIG.  41.  —  A  division  of  the  family  income.     Note  the  items,  and  their  rela- 
tive values.     What  are  the  savings  from  an  income  of  $1000  ? 


AT  OUR   HOMES 


89 


2.  Aside  from  bills  for  physician,  nurse,  and  medicines, 
what  are  the  economic  reasons  for  keeping  in  good  health  ? 

3.  What  are  arguments  to  warrant  expenditures  for  schools 
and  churches  in  a  community  ? 

4.  What  is  the  cost  (a)  of  a  telephone;    (6)  of  electric 
lights;   (c)  of  city  water;   (d)  of  a  daily  newspaper? 

5.  Why  is  it  necessary  to  levy  and  collect  taxes?     For 
what  are  such  moneys  to  be  spent?     Upon  what  basis  is 
anyone's  share  of  taxes  to  be  determined? 

6.  What  argument  is  there  for  including  some  outlay  for 
amusements  in  the  cost  of  living  ?     What  is  a  safe  standard 


FIG.  42.  —  Wholesome  exercise,  and  great  sport. 

whereby  to  judge  if  any  form  of  so-called  amusement  is 
wholesome  and  fit  to  indulge  in?  What  (relatively)  need 
be  the  amount  set  aside  to  spend  for  amusements  ?  Why  so  ? 


90     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

FIRES,   AND   BURNS 

1.  Recall   from   the   lesson  on  Combustion  the  relative 
ease  with  which  kerosene  and  gasoline  ignited,  and  restate 
the  reason  for  it. 

2.  What  is  meant  by  (a)  explosive  vapors;    (6)  inflam- 
mable  gases?     Under   what   conditions   will   explosions   of 
gases  occur?     Explain  the  destructiveness  of  an  explosion 
of  gas.     Why  oftentimes  is  there  an  instant  spread  of  fire 
accompanying  the  explosion?     Why  not  use  water  to  ex- 
tinguish burning  oil  ?     What  material  likely  to  be  at  hand  in 
the  kitchen  may  be  used  ? 

3.  What,  as  a  physician  sees  it,  is  the  nature  of  burns? 
What  is  the  usual  treatment  for  them?     What  is  a  blister? 
How  proceed  to  drain  out  the  fluid  of  a  blister  ? 

4.  Why  are  results   so  likely  to  be  fatal  when  a  large 
area  of  the  body  surface  is  seriously  burned  ?     What  treat- 
ment will  allay  the  torment  from  the  irritated  nerve  ends  of 
the  burned  area  ? 

5.  What  is  meant  by  internal  burns,  and  why  are  they 
likely  to  prove  fatal?     What  is  meant  by  being  suffocated 
by  smoke?    What  is  a  wise  precaution  when  compelled  to 
grope  one's  way  through  smoke  ? 

6.  Explain  the  explosion  when  kerosene  is  poured  upon 
hot  coals  in  a  stove.     What  precautions  should  be  taken  when 
using  gasoline  at  home  to  clean  clothing?     In  case  one's 
clothing  catches  fire  at  any  time,  why  is  it  usually  better 
(a)  not  to  run ;   (6)  not  to  stand  erect  ? 

7.  When    may    illuminating    gas    at  the   kitchen   range 
become  a  source  of  danger  ?     What  danger  is  ever  present  in 


AT   OUR   HOMES 


91 


the  use  of  gas  lights  ?  Wherein  is  there  possible  danger  from 
putting  fresh  coal  into  the  stove  or  the  furnace  just  before 
going  to  bed  ?  What  is  a  wise  precaution  to  take  ? 

8.  What  material  is  used  in  making  the  heads  of  friction 
matches?     Explain  why  they  ignite  from  friction.     When 
may  their  ignition  be  spontaneous  ?     For  what  reason  other 
than   danger  in  their  use  is  the  manufacture  and  sale  of 
matches  containing  yellow  phosphorus  objectionable  ?     What 
is  the  nature  of  safety  matches  ? 

9.  What  is  meant  by  "defective  wiring"  which  is  said 
to  be  the  cause  of  so  many  losses  by  fire?     Why  are  cigar 
stubs  thrown   aside  pecul- 
iarly dangerous  as  sources 

of  fire? 

10.  Discuss   the    nature 
of  some  one  of  the  many 
kinds  of  fire  extinguishers  on 
the  market.      Under  what 
circumstances    may    these 
be  of  large  service  ?     Before 
going  to  bed  in  a  strange 
hotel,  what  is  a  wise  course 
to  take  for  safety  in  case 
there  should  be  a  fire  during 
the  night? 

11.  About   how   much   is    FIQ    43.  -  A  portable  fire  extinguisher. 

the    insurance    charge    for 

three  years    on  a   dwelling    and    household   goods   to   the 

amount  sav  of  three  thousand  dollars  ?     Why  is  the  cost  so 


UasCO,  SOLUTION 


92     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

great  ?    To  about  what  per  cent  only  of  the  real  valuation 
should  property  be  insured  ? 

12.  From  the  bulletins  of  the  State  Fire  Warden  and  the 
regulations  of  local  fire  officials  concerning  prevention  of 
fires,  gather  and  be  able  to  restate  understandingly  some  of 
the  warnings  and  requirements  as  to  (a)  the  accumulation 
of  rubbish,  and  the  starting  of  fires  in  dry  weather ;  (b)  the 
care  of  matches  and  of  inflammable  liquids. 

ACCIDENTS  OTHER  THAN  BURNS 

1.  What  is  the  danger  from  any  slight  wound  where  the 
skin  is  cut  or  torn  ?    What  is  the  chief  value  of  the  "  first  aid  " 
bandages  and  treatments  on  the  battlefield?     Explain  the 
festering  of  slivers  under  the  skin. 

2.  What  is  believed  to  be  one  of  the  offices  of  the  white 
corpuscles  in  the  healing  of  wounds  ?     What  is  generally  true 
of  the  chance  for  recovery  from  wounds,  or  from  surgical 
operations,  of  persons  who  are  users  of  alcoholic  drinks? 
Why  is  this? 

3.  Where  poison  has  been  swallowed,  what  can  be  given 
(a)  as  an  emetic  that  the  stomach  be  freed  of  the  poison 
before  it  can  be  absorbed ;  (6)  to  hinder  absorption,  and 
lessen  any  harmful  action  on  the  stomach  walls?    What 
should  be  an  enforced  rule  of  every  household  as  to  (a)  place 
for  keeping  poisons  of  any  sort  in  the  home ;    (b)  labels  on 
bottles  and  packages  of  poisonous  substances  ? 

4.  Mention  some  of  the  ways  in  which  street  railway 
managers  ask  the  cooperation  of  parents  and  of  the  traveling 
public  in  avoiding  accidents.     Why  must  efforts  in  this 
respect  be  made  year  after  year  ? 


AT   OUR   HOMES  93 

In  which  direction  should  one  face  in  alighting  from  a 
street  car?  Why  is  there  less  likelihood  of  being  thrown 
when  this  rule  is  observed?  Which  hand  should  be  free  to 
grasp  the  railing  (a)  when  mounting  a  car;  (6)  when  dis- 
mounting ? 

5.  What  in  general  is  meant  by  the  "safety  first"  crusade 
in  the  industries  and  in  transportation?    When  are  em- 
ployers of  labor  justly  held  liable  for  accidents  to  employees  ? 
Why  is  there  need  of  State  Inspectors  for  shops,  mills,  fac- 
tories, mines,  and  all  places  where  labor  is  largely  employed  ? 
What  are  the  provisions  in  your  community  (if  any)  for  fire 
escapes  on  buildings  ? 

6.  Why  should  we  condemn  a  person  who  recklessly  im- 
perils the  lives  of  others  as,  for  instance,  one  who  rocks  a 
boat  or  in  a  crowded  house  gives  an  alarm  of  fire  "just  for 
fun  "  ?    What  is  meant  by  "  criminal  negligence  "  on  the  part 
of  a  person,  business  firm,  or  corporation  ? 

7.  What    are   the   tests  for  fitness   (a)  of   engineers  of 
railway  locomotives ;   (6)  of  drivers  of  automobiles  ?    Who 
only  are  allowed  to  run  stationary  engines?    What  ends 
might  be  attained  by  a  system   of    licensing   automobile 
drivers  ? 

8.  Discuss  the  effect  on  the  life  and  usefulness  of  a  man 
from  the  loss  of  one  leg  by  accident  when  a  boy. 


IX.  HOUSEHOLD  CHEMISTRY 
A   REVIEW   OF    SOME    CHEMICAL   CHANGES 

1.  So  common  are  chemical  changes   in    everyday  life, 
and  so  important  are  these  to  our  well-being  and  comfort, 
that  it  will  be  profitable  to  recall  some  already  studied  in 
connection  with   others    more    or    less    familiar    in    home 
affairs. 

What  in  general  is  the  nature  of  the  chemical  change 
that  occurs  in  stoves  and  furnaces  in  warming  our  houses? 
What  explanation  is  there  for  the  heat  produced  in  our 
bodies  ?  What  are  the  products  of  the  oxidation  (a)  of  car- 
bon; (6)  of  hydrogen? 

2.  How  is  it  that  low  temperatures,  lack  of  moisture,  use 
of  preservatives,   and   the   common   processes   of  canning, 
hinder  or  prevent  the  decay  of  organic  foodstuffs?      Name 
some  preservatives  of  foods  that  are  (a)  wholesome;    (6) 
prohibited  because  they  may  be  harmful. 

3.  What   is   the   significance   of   the  term  fermentation? 
What  is  the  general  purpose  of  the  changes  in  the  processes 
of  digestion?     Into  what  stage  of  chemical  change  in  foods 
does  fermentation  lead  if  unchecked?     What  in  some  cases 
is  the  nature  of  the  ailment  called  indigestion?    Why  in 
the  fermentation  of  cider  to  make  vinegar,  and  in  the  sour- 
ing of  milk,  does  the  increase  of  acid  cease  after  a  time? 
Explain  the  destructive  action  on  the  teeth  of  decaying  food 

94 


HOUSEHOLD    CHEMISTRY 


95 


lodged  between  them?  What  is  the  nature  of  the  yeast 
used  in  bread-making?  What  is  secured  through  its  use? 
What  effect  on  the  yeast  has  baking  the  bread  ? 

4.  Where  soil  is  open  and  porous  enough  for  free  access 
of  the  oxygen  of  the  air,  and  at  the  same  time  sufficiently 
moist,  what  chemical  changes  favorable  to  plant  growth 
may  occur  (a)  in  the  humus  of  the  soil ;    (b)  through  the 
agency  of  nitrogen-fixing  bacteria  ? 

5.  What  very  largely  is  the  "dust"  that  accumulates  on 
the  floors  and  furnishings  of  our  homes?     Aside  from  its 
irritating  effects  on  the 

air-passages  and  in  the 
lungs,  what  positive  dan- 
ger is  there  in  breathing 
it?  Where  besides  in 
our  homes  is  there  dan- 
ger from  breathing  dust  ? 
What  is  meant  by  infec- 
tion ?  What  diseases  or- 
dinarily find  their  way 
into  the  body  as  germs  in 
the  air  we  breathe  ? 

6.  What  precautions 
should  be  taken  to  avoid 
filling  the  air  of  rooms 
with  dust  when  sweep- 
ing and  when  dusting? 

What  adds  to  the  dust  nuisance  in  ^schoolrooms  ?  What  is 
a  common  ailment  of  workers  in  factories  where  the  air  is 
filled  with  dust  from  wood,  metal,  or  cloth? 


44.  —  Use  a  damp  cloth,  or  oiled  rag, 
when  dusting. 


96     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

7.  What  is  the  active  chemical  agent  in  the  hypochlorite 
of  lime  (and  "bleaching  powder")  used  to  purify  the  water 
supply  in  city  water  systems,  the  soiled  clothing  from  per- 
sons sick  with  infectious  diseases,  and  the  air  of  cellars  and 
basements  not  kept  well  ventilated?  Name  several  other 
disinfectants  whose  value  lies  in  their  chemical  action  upon 
disease  germs. 

THE   CHEMISTRY   OF   CLEANING 

1.  For  scrubbing  floors,  washing  windows  and  table  dishes, 
and  for  toilet  and  laundry  purposes,  soap  is  employed  to  an 
extent  that  has  led  to  the  statement  that  the  civilization  of 
a  nation  may  be  judged  by  the  amount  of  soap  its  people  use. 

What  in  general  is  true  of  dissolving  oils  and  fats  in  water, 
either  cold  or  warm?  What  is  the  nature  of  butter?  In 
what  size  of  particles  must  its  material  be  when  scattered 
through  milk  ?  Ascertain  the  meaning  of  the  term  emulsion, 
and  show  how  it  applies  to  milk. 

2.  What  is  a  common  effect  upon  the  skin  of  the  use  of 
laundry  soap  ?     Test  some  strong  soap  solution  with  a  strip 
of  red  litmus  paper.     If  it  is  turned  blue,  the  soap  solution 
is  said  to  have  an  alkaline  reaction  (or  alkaline  effect).     De- 
termine by  use  of  litmus  paper  whether  laundry  soap  or 
toilet  soap  is  more  alkaline.     What  should  be  true  of  toilet 
soaps  with  regard  to  an  excess  of  alkali?    Ascertain  the 
nature  of  (a)  scouring  soaps;   (b)  "sapolio." 

3.  Why  is   "hard   water"   objectionable  for  toilet  and 
laundry  purposes  ?     Why  is  cistern  water  more  satisfactory  ? 
Why  is  not  cistern  water  available  for  household  purposes 
everywhere?    Where    "soft   water"    is    not   available   for 


HOUSEHOLD   CHEMISTRY  97 

laundry  use,  what  very  commonly  is  done  before  making  use 
of  soap  in  washing  clothes?  Test  with  litmus  paper  a 
solution  of  any  washing  powder  at  hand  to  determine  its 
nature. 

4.  From    reference    books,    or   other    sources,    ascertain 
what  to  do  in  order  to  remove  from  cloth  (a)  spots  of  com- 
mon ink ;  (6)  coffee  stains ;  (c)  paint  spots ;  (d)  grass  stains. 

5.  How   may  varnished    surfaces,    whether   polished   or 
waxed,  be  cleaned  without  harm  to  them  ?     How  is  tarnish 
removed  from  metals,  such  as  silverware?     How  do  you 
account  for  the  blackening  of  silverware  (a)  by  eggs;    (6) 
by  contact  with  rubber  ? 

6.  Watch  very  closely  the  bleaching  effect  on  small  pieces 
of  cheap  calico,  and  upon  stains  on  white  goods,  when  these 
are  dipped  repeatedly  into  a  solution  of  bleaching  powder 
to  which  strong  vinegar  is  added.     Notice  the  odor  of  the 
bleaching  powder.     What  is  the  chemical  agent  active  in 
the  bleaching? 

ACIDS,  BASES,  AND  SALTS 

1.  Making  use  of  small  strips  of  litmus  paper  test  the 
effect  on  it  of  vinegar  and  of  fruit  juices  (as  lemon,  orange, 
grapefruit,  cherries,  etc.) ;  of  ammonia  water,  limewater, 
and  drinking  water ;  and  of  solutions  of  baking  soda,  washing 
soda,  borax,  soap,  and  common  salt.  Arrange  these  sub- 
stances in  columns  under  the  headings  acid,  alkaline,  and 
neutral,  according  as  the  litmus  paper  is  turned  red,  or  blue, 
or  is  unaffected  in  color. 

To  the  list  as  above  add  a  half  dozen  or  more  tests  of 
other  solutions. 


98       LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

2.  Follow  very  closely  the  results  as  the  teacher  carries 
out  the  following  directions :  —  To  a  solution  of  baking 
soda  in  an  evaporating  dish  add  drop  by  drop  some  dilute 
hydrochloric  acid  (HC1)  till,  as  the  solution  is  stirred  thor- 
oughly, it  does  not  affect  the  color  of  litmus  paper,  i.e., 
till  it  is  neutralized.  If  too  much  acid  is  added  at  any  time, 
more  of  the  soda  solution  may  be  added  drop  by  drop. 
When  the  solution  becomes  neutral,  evaporate  it  to  dryness, 
heating  till  no  more  vapors  pass  off.  Identify  the  solid 
that  remains  by  tasting  it. 

SOME   CARBONATES 

1.  In  the  lesson  on  Combustion  what  was  discovered  re- 
garding the  effect  of  the  expired  breath  upon  limewater 
(CaO2H2)  ?    What  was  the  explanation  of  the  change  in  its 
appearance?    The  precipitate  (the  solid  formed  as  result  of 
chemical  change)  is  calcium  carbonate  (CaCOs). 

2.  Force  air  out  from  the  lungs  through  a  glass  tube  that 
reaches  down  into  lOc.c.  of  limewater  in  a  test  tube,  and 
continue  until  the  limewater  becomes  clear  as  at  first.     The 
solid  particles  of  the  carbonate  of  "lime"  apparently  dis- 
solve.    Test  the  liquid  with  litmus  paper  to  determine  its 
nature. 

To  explain  what  has  occurred,  it  may  be  supposed  that  car- 
bon dioxide  combines  with  the  water  as  shown  in  the  equation 
CO2  +  H2O  —>  H2COs  (carbonic  acid),  and  this  in  turn  with 
the  limewater  thus :  —  CaO2H2  +-H2CO8  ->  H2O  +  CaCO3. 
But  when  an  excess  of  H2CO3  has  been  formed  by  reason  of 
continued  breathing  of  CO2  into  the  limewater,  the  further 
change  whereby  the  limewater  becomes  clear  again  may  be 


HOUSEHOLD   CHEMISTRY  99 


represented  in  the  equation  CaCOs  +  H2CO3  —  >H2Ca 

in  which  the  resulting  new  substance  known  as  acid  calcium 

carbonate  is  soluble  in  water. 

Whether  these  chemical  changes  occur  as  a  series  of  steps 
in  the  order  indicated,  or  are  more  or  less  coincident,  is  of 
far  less  importance  than  it  is  to  have  set  forth  in  the  equa- 
tions that  which  is  known  to  be  true  concerning  what  sub- 
stances as  factors  enter  into  the  chemical  change,  and  what 
substances  result  as  products. 

3.  Learn  definitions  for  acid,    base,  and  salt  as  used  in 
Chemistry.     Show  very  definitely  how  the  substances  whose 
formulae  are  CaCOa,  CaO2H2,  and  H2CO3,  respectively,  meet 
these  conditions.     It  will  be  noted  that  in  the  formula  for 
the   acid   calcium   carbonate   there   appears   not   only   the 
metallic  atom  Ca  from  the  base,  and  the  radical  CO8  from  the 
acid,  but  some  H  from  the  acid  appears  also  in  the  formula 
of  the  salt.      This  formula  H2Ca(CO3)2  is  a  good  illustra- 

tion of  the  class  of  so-called  acid  salts.     It  must  be  remem- 

• 

bered,  however,  that  it  is  upon  the  presence  of  the  hydrogen 
atoms  in  the  molecule  of  the  acid  salt,  and  not  upon  the 
effect  shown  by  litmus  paper,  that  the  classification  of  salts 
as  normal  and  acid  depends.  In  the  case  of  the  salt  known 
as  acid  sodium  carbonate  (HNaCOs)  the  solution  as  shown 
by  use  of  litmus  paper  is  strongly  alkaline. 

4.  Note  the  appearance  and  taste  of  both  sodium  car- 
bonate (Na2C03)  and  acid  sodium  carbonate.     The  latter  is 
"baking  soda,"  and  the  former  is  known  as  "sal-soda," 
and  as  "washing  soda."    Test  the  gas  given  off  as  a  little 
hydrochloric  acid  is  added  to  portions  of  each  of  these 
salts  in  test  tubes.     (Hold  dowh  in  the  tube   above  the 


100     LABORATORY   LESSON&   IN   GENERAL   SCIENCE 

effervescing  liquid  a  glass  rod  having  a  drop  of  clear  lime- 
water  on  its  lower  end.  This  is  the  usual  test  for  carbonates.) 
Repeat  the  test,  using  in  turn  a  small  lump  of  marble,  and 
then  one  of  limestone.  Try  bits  of  egg  shell,  and  of  any 
other  shells  at  hand.  Test  any  fragments  of  rock  provided, 
and  pieces  of  old  mortar.  Be  sure  to  note  about  what  por- 
tions (if  any)  of  the  marble  and  of  the  limestone  fail  to  dis- 
solve in  the  acid.  Account  for  any  such  failure. 


X.  THE  HOME  SURROUNDINGS 


A   GARDEN   IN   THE   HOME   LIFE   OF   A   FAMILY 

1.  Aside  from  the  money  value  of  its  produce,  what  are 
excellent  reasons  for  having  a  small  but  well-kept  garden  con- 
nected with   every 

home?  Name  some 
of  the  common 
amusements  for  a 
boy  in  town. 
Wherein  is  an  ac- 
tive interest  in  the 
home  garden,  and 
the  employment  in 
it  of  one's  spare 
moments,  superior 
to  any  of  them? 
What  part  may 
the  mother  and 
daughters  of  a 
family  have  in  the 

Care    of    a    garden  ?    FIG.  45.  —  Counting  the  profits  from  the  garden. 

2.  Explain  how  it  is  that  in  the  care  of  the  home  garden 
a  boy  may  learn  (a)  to  know  the  conditions  for  plant  growth ; 
(6)  to  understand  economic  values  in  home  life ;    (c)  to  as- 
sume responsibilities  and  to  discharge  duties. 

101 


102   LABORATORY  LESSONS  IN  GENERAL  SCIENCE 

3.  Trace  a  relation  (a)  between  lack  of  home  occupations 
on  the  one  hand,  and  vicious  and  evil  ways  on  the  other; 
(6)  between  industry  and  capable  management  in  the  small 
affairs  of  life  at  home  during  childhood,  and  the  likelihood 
of  becoming  worthy  and  successful  men  and  women. 

4.  In  order  to  plan,  plant,  tend,  and  carry  through  to 
success  a  season's  gardening,  (a)  what  characteristics  must  be 
possessed  (or  developed)  other  than  strength  of  muscle ;    (6) 
what  lessons  not  of  books  are  likely  to  be  learned?     How 
may  "initiative"  (m-ish'i-a-tiv)  be  developed  in  the  care  of 
a  garden? 

5.  Why  is  it  better  to  have  the  care  of  a  garden  at  home 
than  to  depend  upon  a  school  garden  ?    On  the  other  hand, 
what  excellent  purposes  are  served  by  a  school  garden? 
What  application  here  has  the  saying,  "  What  is  worth  doing 
at  all  is  worth  doing  well"? 

THE   CARE   OF  A   GARDEN 

1.  In  planting  small  seeds  like  beet,  onion,  lettuce,  radish, 
turnip,  carrot,  parsnip,  (a)  about  how  far  apart  should  the 
rows    be    placed ;     (6)  about    how    far    apart    should    the 
plants  be  allowed  to  grow;     (c)   about  how  close  should 
the  seeds  be  sown ;   (d)  about  how  deep  should  the  seeds 
be  covered  ?     How  deep  should  the  soil  have  been  over- 
turned and  made  loose  for  these  seeds?    Why  should  the 
surface  layer  be  raked  much  more  than  is   necessary  to 
make  it  smooth? 

2.  About  how  far  apart  should  the  rows  be,  and  how  far 
apart  the  plants  in  a  row,  for  (a)  corn,  potatoes,  beans; 
(b)  cabbage,  tomato,  and   sweet   potato   plants  as  trans- 


THE   HOME  SURROUNDINGS  103 

planted?  What  is  the  advantage  of  transplanting  over 
putting  the  seeds  in  place?  What  special  preparation  of 
the  ground  is  made  for  sweet  potato  plants  ?  What  is  the 
manner  of  planting  the  common  potato  ?  Why  is  there  less 


FIG.  46.  —  At  work  in  the  garden. 

need  of  care  in  the  preparation  of  the  soil  for  corn  and  po- 
tatoes than  for  onions,  radish,  and  lettuce  ? 

3.  Examine  closely  the  various  garden  seeds  provided  in 
the  small  labeled  vials  so  you  may  be  sure  of  making  no 
mistakes  later  when  you  will  be  required  to  recognize  at  sight 
and  to  name  any  kind  given  you  from  unlabeled  lots. 

What  is  meant  by  a  seed?  What  are  the  conditions  under 
which  the  life  dormant  within  it  becomes  manifest? 


104     LABORATORY   LESSONS  IN   GENERAL   SCIENCE 


4.  For  what  chief  reason  other  than  keeping  down  weeds 
ought  there  to  be  frequent  stirring  of  the  surface  layer  of 
soil  throughout  the  growing  season  ?  Aside  from  the  untidy 
appearance  they  give,  what  harm  is  there  in  allowing  weeds 
to  grow  ?  What  course,  if  followed  consistently,  will  destroy 
the  weeds  of  a  garden  during  the  growing  season  with  the 
least  outlay  of  time  and  strength?  Under  what  condition 
of  the  soil  is  it  more  harmful  than  beneficial  (ben-e-fish'al) 

to  work  it  ?  Why  is  it  well 
to  plow  (or  spade)  some 
gardens  late  in  the  fall  ? 

5.  About  how  long  after 
planting   may   one   expect 
ready  for  use   (a)   radish; 
(6)  green    peas;    (c)  string 
beans  ?    How  may  a  supply 
of  radish  and  of  beans  be 
secured  at  intervals  (or  in 
succession)  ?    What  differ- 
ent course  may  be  followed 
with  peas  and  with  corn? 

6.  On  one  side  of  your 
sheet  of  paper  represent  a 
garden  plot  30   feet  X  40 
feet,  using  the  scale  \  inch 

=  one  foot.     Represent  on  it  (a)   by  the  use  of  lines  of 
suitable  length  and  at  correct  distances  apart,  garden  stuff 
sowed  (or  set)  in  rows ;  (6)  by  the  use  of  circles  at  correct 
distances  apart  that .  which  is  planted  (or  set)  in  hills. 
By  the  use  of  figures  on  these  lines,  and  within  these  cir- 


FIG.  47.  —  String  beans.  Ready  for 
household  use,  or  for  a  lesson  in 
botany. 


THE  HOME  SURROUNDINGS 


105 


cles,  refer  to  a  numbered  list  at  one  side  of  your  sheet  that 
names  the  kinds  of  stuff  you  would  raise  in  your  garden. 

7.  Name  both  advantages  and  disadvantages  (a)  from 
alternating  rows  of  corn  and  of  potatoes;    (6)  from  having 
squash  or  pumpkin  planted  in  among 

the  corn. 

8.  Why   is   it    undesirable  to   have 
trees,  shrubs,  or  bushes  in  the  garden 
space?     What  small  fruits  may  easily 
be  grown  out  at  one  side  of  the  garden  ? 

TREE   PLANTING 

1.  Have  you  ever   helped   plant    a 
tree  ?   What  kind  of  tree  did  you  plant  ? 
Was  it  for  shade,  or  for  fruit  bearing? 

2.  In  your  locality  what   are  good 
kinds   of   trees   to   plant    for    shade? 
Where  may  these  be  obtained  ?    About 
what  is  their  cost  per  tree?    What  is 
a  good  choice  of  shade  tree  for  planting 
as  to  (a)  age ;   (6)  diameter ;  (c)  height  ? 

TT71  11  !    i  „         FIG.  48.  —  Before   set- 

Why  not  use  older  and  larger  trees  tor       ting  out  a  young  tree, 

transplanting?     In  what  respects  is  it       J*f    *°P    **d.  r,oot* 

should  be    cut   back 

generally  better  to  purchase  trees  that 
have  been  grown  in  a  local  nursery 
than  to  get  them  from  a  distant  part 
of  the  country  ? 

3.  Why  will  the  growth  of  a  newly  set  tree  necessarily 
be   slow  at  first?    In   order  that  food  material  for  the 


as  indicated  by  the 
dotted  lines.  The 
top  will  then  have 
the  appearance  shown 
in  a. 


106     LABORATORY   LESSONS  IN   GENERAL   SCIENCE 

growth  of  plants  can  be  taken  in  through  the  roots,  in  what 
condition  must  this  material  be  ? 

4.  That  the  young  tree  be  well  nourished  from  the  first 
after  transplanting,  (a)  what  form  of  root  is  desirable ;  (b) 
what  should  be  the  condition  of  the  soil  filled  in  around  the 
roots ;  (c)  why  pour  water  about  the  roots,  and  what  amount 
should  be  used;  (d)  why  press  the  earth  firmly  about  the 
roots  ? 

5.  Why  is  such  great  harm  done  in  an  exposure  of  the 
rootlets  to  air  and  sun  even  for  a  very  short  time?    While 
the  planting  of  trees  is  going  on,  how  may  the  roots  of  those 
awaiting  planting  be  kept  from  injury?     What  purpose  is 
served  by  leaving  two  or  three  inches  of  top  soil  loose  and  o'ry 
around  each  tree  planted?     WThat  is  meant  by  "heeling  in" 
trees  for  later  planting  ? 

6.  In  what  manner  may  young  trees  newly  set  be  pro- 
tected (a)  from  ill  effects  of  heavy  winds ;   (6)  from  animals  ? 
Why  is  it  harmful  to  the  young  tree  (a)  to  break  off  its 
branches;    (6)  to  pull  it  about,  loosening  it  in  the  ground? 
Why  is  it  harmful  to  tramp  the  soil  about  the  tree  by  run- 
ning over  it? 

7.  What  is  the  chief  use  of  leaves  to  plants?     In  trans- 
planting trees  why  is  it  generally  best  to  trim  off  almost  all 
side  branches,  and  to  cut  back  the  top  ?     When  does  a  young 
tree  become  able  to  provide  for  much  leaf  surface?    What 
is  transpiration  in  plants? 

8.  Where  a  young  tree  is  to  be  grown  for  fruit-raising, 
what  shape  of  top  is  desirable  ?    Why  so  ?    Why  is  it  better 
to  prune  a  little  every  year  and  not  at  long  intervals  ?    Why 


THE   HOME  SURROUNDINGS 


107 


is  there  need  to  give  more  attention  to  pruning  when  the 
trees  are  young  ?  Why  should  the  branches  be  cut  off  close 
up  to  the  trunk  (or  main 
limbs)  ? 

What  different  manner  of 
trimming  is  followed  when 
trees  are  for  shade  ?  What 
is  the  effect  upon  the  tops 
of  trees  when  they  are  set 
too  close? 

9.  What  are  common 
causes  for  transplanted  trees 
dying  (a)  when  young; 
(6)  when  grown  large?  Of 
what  advantage  to  trees  is 
it  to  have  the  ground  under 
them  mulched  by  leaves,  or 
shaded  by  some  growth? 

10.   Read  the  poem  "Planting  of  the  Apple   Tree"    by 
Whittier,  and  memorize  at  least  one  stanza. 

TREES   OF  THE   NEIGHBORHOOD1 

1.  The  elm  is  so  common  a  tree  that  it  is  well  known 
generally.     Its  characteristics,  too,  are  well  marked.     De- 
scribe the  location  briefly  but  definitely  of  a  large  elm  grow- 
ing in  your  neighborhood.     Tell  where  several  others,  large 
or  small,  are  to  be  found. 

2.  Name  differences  in  the  appearance  of  the  bark  (a) 
on  older  and  on  younger  trees ;   (6)  on  their  twigs  and  on  the 
trunks. 

1  See  footnote  of  lesson  on  Temperature  Records. 


FIG.  49.  —  How  to  prune  trees. 


108     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

3.  Does  the  main  stem  of  the  elm  usually  continue  up- 
ward through  the  tree  top  or  subdivide  into  large  limbs? 
Is  the  growth  of  small  twigs  (the  "spray  ")  usually  scanty 

or  abundant  ?  What  bearing  has 
this  on  the  elm  as  a  shade  tree  ? 
In  general  are  the  outer  branches 
rigid  or  drooping? 

4.  From  a  study  of  elm  leaves  * 
state  (a)  whether  the  leafstems 
(petioles)  below  the  broad  blades 
are  long  or  short ;  (6)  what  the 
general  shape  of  the  blade  is; 
(c)  what  kind  of  margin  the  leaf 
has ;  (d)  what  difference  there  is 
in  the  feeling  of  the  upper  and 
the  lower  surfaces ;  (e)  what  is  a 

noticeable   characteristic   of  the   two  sides   of  the  blade; 
(/)  just  how  the  leaves  are-  arranged  along  the  stem. 

5.  After  an  examination  of  the  buds  on  some  of  the  small 
branches  of  the  elm  tree,  state  (a)  their  relative  locations  on 
the  stems,  and  their  location  with  reference  to  the  places  of 
leaves  (or  leaf  scars) ;  (6)  their  general  form ;   (c)  what  their 
outer  covering  is,  and  what  is  found  within  the  bud. 

6.  Pick  out  elm  seeds  from  a  mixed  lot  of  seeds  of  trees, 
and  examine  them  closely.     Make  a  drawing  of  a  cluster  of 
elm  seeds. 

Learn  the  appearance  of  the  flowers  of  the  elm  tree  (from 
pictures  if  necessary).  State  their  location  on  the  stems  with 
reference  to  the  leaves.  Be  on  the  lookout  in  the  springtime 


FIG.  50.  —  A  tree  in  winter. 


Use  good  cuts  in  books  if  necessary. 


October  18th. 

FIG.  51.  —  Elm  twigs,  buds,  flowers,  and  leaves. 

109 


110    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

to  recognize  elm  flowers,  and  be  sure  to  verify  what  is  shown 
in  the  pictures. 

7.  To  what  uses  is  elm  wood  put  other  than  for  fuel? 
What  is  its  relative  value  for  lumfeej?     Discuss  how  the 

S"      'v  £ 

cutting  of  the  forests  of  the  United  States  Tias  contributed 
to  the  high  cost  of  living. 

8.  Arrange  alphabetically  in  a  column  a  l;ist  of  five  or 
more  shade  trees  known  by  you.     In  like  manner  in  other 
columns,  write  (a)  the  names  of  five  fruit  trees  ;  (b)  the  names 
of  five  trees  of  which  you  have  read  or  heard,  but  which 
otherwise  are  unknown  to  you. 

9.  After  such  instruction  as  may  be  needed  in  the  use  of 
the  "Key"  in  Farmers'  Bulletin  No.  468,  make  use  of  your 
copy  as  you  come  and  go  outside  school  to  verify  your  list 
of  shade  trees,  employing  it  with  different  trees  of  the  same 
kind  till  you  are  perfectly  familiar  with  the  distinctions  it 
makes. 

State  what  you  have  noted  of  different  trees  of  the  same 
kind  as  to  form  and  general  appearance  even  when  age  and 
conditions  of  growth  are  much  the  same.  Note,  too,  that  there 
are  varieties  of  the  same  kind  of  tree,  e.g.,  there  are  several 
different  kinds  of  elm  with  marked  characteristics  that  in- 
variably distinguish  them. 

10.  In  a  tabulated  form  suitably  arranged  under  appro- 
priate headings,  write  in  lines  opposite  each  of  the  five  shade 
trees  named  in  paragraph  8  the  characteristics  of  each 
kind  of  tree.  (Write  lengthwise  of  the  page,  and  so  that 
the  same  items  for  all  trees  fall  in  the  same  column.)  This 
makes  it  possible,  by  following  down  a  column,  to  note  the 


THE   HOME  SURROUNDINGS  111 

differences  among  these  trees  in  any  one  respect.  In  an  ele- 
mentary way  this  grouping  of  facts  is  a  "Key"  for  the 
identification  of  these  trees. 

11.  Outside  of  school  hours  make  a  sketch  of  some  one  of 
the  shade  trees  you  named,  showing  its  form  and  manner 
of  branching.  State  (by  map  or  otherwise)  just  where  this 
tree  is  to  be  found.  Hand  in  the  sketch. 

Using  the  Key  of  Farmers'  Bulletin  468,  and  any  available  reference 
books  on  trees,  determine  the  name  and  variety  of  a  large  number  of 
trees  in  the  immediate  vicinity  —  trees  which  before  were  unknown  to 
you.  Cultivate  the  acquaintance  of  these  trees  till  you  are  sure  of 
recognizing  them  at  sight,  and  have  an  interest  in  their  growth  and 
well-being  as  friends  of  yours. 

Be  prepared  to  state  in  writing  (as  an  examination  for  school  credit 
it  may  be)  the  name  and  variety  of  any  designated  tree  or  trees  of  the 
neighborhood,  together  with  the  characteristics  upon  which  you  base 
your  decision.  (Be  sure  to  include  in  your  studies  some  of  the  ever- 
greens and  ornamental  trees  of  the  vicinity.) 

SOME   PLANT   STUDIES 

1.  Note  the  general  form  of  the  roots  of  some  corn  plants 
unearthed  from  flower  jars  in  which  they  have  been  growing 
in  the  room.1  Flatten  one  of  the  best  of  these  specimens 
against  white  cardboard,  and  make  a  drawing  to  represent 
its  appearance.  The  roots  of  the  grasses  and  of  the  grains 
are  very  generally  of  this  fibrous  type.  Gardeners,  florists, 
and  nurserymen  in  many  instances  transplant  trees,  shrubs, 
and  other  plants  for  the  express  purpose  of  causing  them  to 
form  a  large  mass  of  fibrous  roots. 

1  Provision  for  these  studies  must  be  made  ahead  of  the  time  set  for  this 
lesson. 


112    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 


2.  Select  a  good  specimen  of  long  scarlet  radish  (likewise 
grown  in  the  room),  and  make  a  drawing  of  it  as  an  illustra- 
tion of  a  taproot.  The  root  of  the  dandelion  is  of  this  form, 

and  trees  that  have 
never  been  trans- 
planted may  have  one 
or  several  such  main 
roots.  Plants  with 
taproots  are  likely 
to  become  strongly 
embedded. 

3.  What    is   the 
general  purpose  (a)  of 
the  roots  of  plants; 
(6)    of    their   stems ; 
(c)   of  their   leaves? 
What  may  be    con- 
sidered the  primary 
purpose     of     flowers 
and  seeds? 

4.  Examine    some 
stems  (stalks)  of  corn 

and  of  the  grains,  and  compare  their  structure  with  that 
of  some  young  growths  of  trees  or  shrubs.  Examine  some 
vigorous  shoots  of  last  season's  growth  of  various  trees 
(a)  for  arrangement  of  leaves  (or  leaf  scars)  on  the  stem, 
noting  whether  it  is  alternate,  opposite,  or  whorled;  (b)  for 
places  of  the  buds  with  reference  to  these  leaves.  Some 
stems  are  climbers,  as  the  hop  plant,  morning  glory,  etc. ; 
others  are  creepers,  as  the  strawberry.  The  common 


FIG.  52.  —  Taproot  of  the  dandelion. 


THE  HOME  SURROUNDINGS 


113 


potato  is  an  underground  stem  known  as  a  tuber,  and  its 
"eyes"  are  buds  from  which  new  potato  plants  will  grow 
as  "sprouts." 

5.  Out  of  a  supply  of  leaves  brought  into  the  room  by  the 
teacher  select  specimens  to  illustrate  parallel-veined,  feather- 
veined,  and    palmately-veined   leaves.1      Make   drawings    of 
each  kind. 

6.  Make  drawings  of  leaves  that  are   (a)   simple;     (b) 
palmately  compound  and  pinnately  compound.     (Pinnate  = 
feather-like.) 

7.  Make  drawings  to    show  leaves  whose  margins  are 
entire,  toothed,  and  lobed,  choosing  under  direction  of  the 
teacher  the  best  specimens  at  hand. 

8.  Write  in  a  column  a  list  of  four  kinds  of  leaves  repre- 
sented in  the  supply  of  fresh  leaves  at  hand  (or  of  mounted 
specimens).     At  the  right  of  each  such  leaf-name  write  a 
single  descriptive  word  under  each  of  the  following  head- 
ings, so  arranging  these  descriptive  terms  that  they  fall  into 
columns  thus :  — 


NAME  OP 
LEAF 

VEINING 

MARGINS 

KIND  (IF 
COMPOUND) 

ARRANGEMENT 
ON  STEM 

KIND  OF 
SURFACES 

1 

— 

— 

— 

— 

— 

— 

2 

— 

— 

— 

— 

— 

— 

3 

— 

— 

— 

— 

— 

— 

4 

— 

— 

— 

—  - 

— 

— 

1  See  illustrations  in  Botany  texts,  and  other  books. 
I 


114    LABORATORY   LESSONS   IN   GENERAL  SCIENCE 


FIG.  53.  —  Type  forms  of  leaves. 


THE   HOME  SURROUNDINGS  115 

BIRDS  ABOUT   OUR  HOMES1 

1.  Make  a  list  of  ten  birds  that  are  so  well  known  to  you 
that  you  recognize  them  and  can  name  them  at  sight. 

2.  Name  the  several  particulars  in  which  these  birds  of 
your  list  are  alike  —  those  features  of  build,  covering,  ac- 
tivities, and  manner  of  life  that  are  common  to  all.     In  what 
respects  do  they  all  differ  from  domestic  fowls  such  as  the  hen  ? 

3.  Tell  what   there  is  characteristic  of   any  four  of  the 
birds  named  whereby  you  identify  them.     (Include  details 
of  their  nesting,  rearing  of  young,  migrations,  relations  to 
men  and  to  other  birds,  their  songs,  and  the  differences  in 
plumage  of  male  and  female.) 

4.  Make  another  list  of  birds  known  to  be  more  or  less 
common  in  your  neighborhood  but  not  recognized  by  you 
at  sight  with  certainty.     Underscore  the  names  of  any  in  this 
list  that  you  think  you  might  be  able  to  call  by  name  if 
you  should  see  them. 

5.  Select  one  bird  from  your  first  list  and  write  a  brief 
description  of  it,  setting  forth  its  characteristics  in  a  way 
that  would  materially  assist  another  person  in  recognizing 
the  bird. 

6.  Make  another  list  of  birds  whose  names  are  familiar 
but  which  you  would  not  recognize  at  sight.     Group  these 
names  into  (a)  those  of  the  region  where  you  live ;   (b)  those 
of  foreign  parts. 

Two  weeks  before  the  close  of  this  work  in  General  Science  hand  in 
a  list  of  the  birds  that  you  have  learned  to  know  between  now  and  then, 
telling  when  and  where  you  have  seen  them,  and  upon  what  they  seemed 

to  feed. 

1  See  footnote  of  lesson  on  Temperature  Records. 


XI.  LOCAL  INDUSTRIES 
SOME   OCCUPATIONS    OF   THE    COMMUNITY 

1.  Name  a  carpenter  whom  you  know.     Tell  something 
of  the  work  he  does.     Of  whom  does  he  get  lumber  for  his 
work  ?     Name  several  people  in  town  who  are  (a)  carpenters ; 
(b)  lumber  dealers.     Why  are  there  fewer  lumber  dealers 
than  carpenters?     How  much  does  a  carpenter  get  for  a 
day's  work?     How  does  a  lumber  dealer  get  paid  for  his 
time  and  labor  ?     What  sooner  or  later  is  the  business  result 
when  a  lumber  dealer  cannot  sell  his  lumber,  or  sells  it  for 
less  than  cost?     Name  some  differences  between  making  a 
living  by  working  at  a  trade  and  by  engaging  in  business. 
At  what  time  of  year  is  a  carpenter  likely  to  be  out  of  work  ? 
What  expenses  may  a  lumber  dealer  have  when  there  is  no 
business  for  him  ? 

2.  Whence    comes  the    lumber   that    the    dealer   sells? 
How  is  it  brought  to  him?     From  what  is  lumber  made? 
Why  do  we  not  get  lumber  nearer  home  just  as  we  get  hay 
and  corn?     What  will  be  done  when  the  supply  of  lumber 
from  the  sources  named  is  exhausted?     What  difference  in 
the  cost  of  lumber  will  this  cause?     Give  several  illustra- 
tions of  other  material  that  is  already  substituted  for  wood. 
In  what  other  ways  is  the  timber  supply  of  the  country  being 
conserved  to  some  extent?    What  are  the  special  duties  of 
the  Forest  Service  of  the  United  States  ? 

116 


LOCAL   INDUSTRIES 


117 


3.  Who  in  your  community  are  railroad  men,  i.e.,  in 
the  employ  of  the  railways?  Name  others  who  are  em- 
ployed in  conveying  freight,  express,  and  people  to  and 
from  the  station.  What  would  be  true  of  the  business  of 
these  men  if  there  were  no  railroad  into  town  ?  What  besides 
lumber  is  shipped  as  freight  into  your  town  by  railroad? 


FIG.  54.  —  An  artificial  waterway. 

What  other  means  for  freight  transportation  have  some 
towns?  Name  a  place  having  transportation  facilities  not 
possessed  by  your  town.  How  is  the  size  of  towns  affected 
by  having  ample  facilities  for  transportation?  Why  is 
this  so  ? 

4.   What  other  supplies  are  commonly  handled  by   the 
lumber  dealer?     Where  does  he  get  them?     How  are  they 


118     LABORATORY   LESSONS   IN   GENERAL  SCIENCE 

brought  to  him  ?  Why  are  they  brought  so  far,  and  at  such 
cost?  Who  determines  what  the  freight  charges  shall  be? 
What  is  involved  in  the  determination  of  what  is  a  fair  and 
reasonable  charge?  Why  does  not  every  man  bring  in  his 
own  supplies?  Why  are  not  competing  lines  of  transporta- 
tion established  to  lessen  freight  rates?  How  is  it  that 
inland  waterways  regulate  freight  rates? 

5.  Name  other  lines  of  business  that  furnish  the  car- 
penter   supplies    (a)    for    building    purposes;    (6)    to   live 
upon.     Name  several  men  you  know  engaged  (a)  in  trade 
(business) ;     (6)   in  agriculture.     In  this  latter  case  name 
some  of  the  various  kinds  of  farm  work  carried  on  by  them. 
Why  does  one  farmer  raise  corn  and  alfalfa  and  hogs,  and 
another  keep  cows  for  butter-making  ? 

6.  Under  the  heading  "Agriculture"  make  a  list  of  the 
occupations  in  which  men  engage  that  have  to  do  directly 
with  farming,  such  as  stock-raising,  fruit-raising,  dairying, 
gardening,  general  farming,  etc.     Underscore  those  that  are 
followed  in  the  community  round  about  you. 

7.  Make  a  list  of  the  industries  other  than  trades  and 
agricultural  pursuits  represented  in  your  community. 

8.  Make  a  list  of  the  various  trades,  such  as  blacksmith, 
mason,  etc. 

9.  Name  the  professions  represented  in  your  town,  — 
lawyer,  physician,  etc. 

10.  List  other  occupations  of  men,  —  dentist,  grocer,  milk- 
man, printer,  etc.,  grouping  them  under  one  or  the  other  of 
the  headings  "Producers,"  or  "Consumers."  State  wherein 
some  who  are  classed  as  consumers  are  to  an  extent  pro- 
ducers, and  those  classed  as  producers  also  are  consumers. 


LOCAL  INDUSTRIES  119 

11.  Name  several  occupations  in  which  women  are  en- 
gaged outside  the  home  in  earning  a  livelihood.     In  what 
respects  does  successful  management  of  household  affairs 
demand  higher  intelligence  of  a  woman  than  shop  or  office 
work  ?     In  what  respects  must  the  housewife  exercise  a  high 
degree  of  business    ability  in   expending  that  part  of  the 
family  income  used  to  meet  the  cost  of  living? 

12.  Give   arguments  against  child  labor   in  community 
life.     Why   is    it    desirable    to    have    some    employment, 
either  indoors  or  out,  for  children  at  home?     Name  some 
home  duties  for  which  children  may  assume  responsibility  ? 
Wherein  may  there  be  educational  value  in  such  duties  ? 

MODERN   INDUSTRIAL   LIFE 

1.  Explain  the  fact  that  the  shoemaking  industry,  for 
example,  is  centered  in  a  relatively  few  localities,  with  a 
daily  output  of  thousands  of  pairs  of  shoes  for  a  single  factory, 
rather  than  in  small  establishments  scattered  all  over  the 
country.     Where  must  the  people  live  who  are  engaged  in 
any  such  industry?  What  is  the  effect  of  these  conditions 
upon  the  distribution  of  population  in  the  country  as  a 
whole? 

2.  Compare  the  advantages  enjoyed  by  people  who  move 
to  centers  of  industrial  life  with  those  commonly  experienced 
in  the  more  sparsely  settled  rural  communities.     Name  some 
of  the  disadvantages  to  a  wage-earning  people  incident  to 
life  in  excessively  congested  quarters.     What  are  some  of 
the  reasons  that  lead  to  the  crowding  together  of  different 
industries  in  a  small  district  of  a  city  instead  of  choosing 
locations  more  widely  scattered? 


120     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

3.  What  relation  is  likely  to  exist  between  any  chances  of 
advancement  in  position  for  a  wage  earner,  and  his  educa- 
tional and  industrial  preparation  for  his  work?  What 
conditions  may  overrule  this  natural  association?  Name 


FIG.  55.  —  When  work  hours  are  over. 

some  factors,  wholly  apart  from  the  efficiency  of  the  individ- 
ual worker,  that  enter  into  the  computation  determining 
the  pay  that  can  be  given  employees  in  an  industrial  concern. 

4.  How  large  a  part  has  any  one  person  in  the  making  of 
a  shoe,  or  the  making  of  an  engine?  Of  what  character  is 
the  work  of  a  shop  or  factory  operative  generally  ?  What  is 
the  effect  upon  a  person  mentally  and  physically  who  is 
engaged  day  after  day  as  an  attendant  upon  a  machine  ? 
What  different  results  may  follow  the  use  of  machines  by 


LOCAL   INDUSTRIES 


121 


skilled   mechanics,    professional    men,    builders,    engineers, 
and  others  to  facilitate  the  execution  of  any  undertaking  f 

5.  Why  should  years  of  regular  attendance  at  school 
contribute  much  towards  keeping  persons  who  operate 
machines  masters  of  their  labors  rather  than  slaves  to  the 


FIG.  56.  —  One  person  can  supervise  many  machines  in  the  spinning  room 
of  a  cotton  factory. 

machine?  How  is  it  that  much  attendance  at  schools  may 
sometimes  fail  to  make  a  person  an  efficient  worker  in  life's 
affairs?  In  addition  to  the  information  one  may  have 
acquired,  what  is  characteristic  of  a  person  who  is  really 
"educated"? 


122     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

SANITARY  CONDITIONS  FOR  THE  WAGE  EARNER 

1.  From  personal  knowledge,  or  as  you  have  heard  the 
facts  told,  write  an  account  of  the  hardships  that  have  be- 
fallen some  family  by  reason  of  accident,  illness,  or  other 
disability  directly  traceable  to  conditions  of  employment  or 
to  the  culpable  negligence  either  of  the  individual  or  of  his 
employer.     Observe  in  a  general  way  the  following  condi- 
tions for  the  narrative  :  — 

(a)  Confine  yourself  quite  closely  to  known  facts,  and 
discriminate  between  what  is  more  important  and  what  is 
incidental.  Avoid  setting  forth  as  facts  things  only  sur- 
mised to  have  been  true,  or  that  are  merely  the  opinions  of 
yourself  and  of  others  concerning  the  case. 

(6)  Indicate  obvious  measures  to  be  taken  by  the  em- 
ployer and  by  the  employee  for  the  prevention  of  further 
cases  of  the  kind. 

(c)  The  name  of  the  person  of  whose  case  you  write  is 
unnecessary.  Speak  of  Mr.  A  if  you  desire.  Have  in  mind 
the  hardships  and  losses  not  only  of  the  individual  but  of 
the  family  and  community  as  well. 

2.  In  the  list  of  employments  given  below,  injury  to  the 
workers  is  likely  to  occur  unless  special  precautions  are  taken 
to  remove  dust-laden  air.     Copy  the  list,  and  to  it  add  three 
other  industries  in  which  dust  is  a  menace  to  the  health  of 
the  workers. 

tool  grinding  cotton  spinning  flour  making 

sand  blasting  wool  finishing  foundry  work 

3.  In  what  ways  is  danger  to  health  from  dust  in  factories 
and  shops  lessened  or  entirely  eliminated?     How  is  it  that 
long-continued  breathing  of  dust-laden  air,  otherwise  pure 


LOCAL  INDUSTRIES  123 

and  free  from  germs,  leads  finally  to  tuberculosis  ?  What  is 
the  relation  between  warfare  upon  tuberculosis,  and  the 
prohibition  of  spitting  on  sidewalks  and  on  floors  of  mills 
and  factories?  In  what  sense  does  the  statement  that 
"society  has  the  right  to  protect  itself"  apply  here?  In 
matters  of  contagious  diseases  what  is  done  to  protect  people 
generally  ?  What  may  very  properly  be  done  with  those  who 
at  school  and  elsewhere  wilfully  and  persistently  refuse  to 
regard  the  rights  and  welfare  of  others  in  matters  of  health 
and  decency  ? 

4.  In  what  very  true  sense  is  the  school  a  workshop  ?    A 
good   schooling    should   give  what   advantages  to   anyone 
when  seeking  employment  at  any  time  ?     What  besides  good 
health  and  physical  endurance  is  desired  of  those  who  in 
office,  shop,  and  factory  are  put  in  charge  of  complicated  and 
expensive  machines,  and  are  called  upon  to  use  time  and 
material  to  the  very  best  advantage  ?     Aside  from  skill  in 
workmanship,  what  is  meant  by  "an  intelligent  workman" 
in  any  of  the  callings  of  life  ?     What  is  it  for  an  employee  to 
"take  the  initiative"? 

5.  One  of  the  purposes  of  attending  school  is  to  become 
more  capable  and  more  efficient  in  the  affairs  of  life  than 
would  otherwise  be  possible.     State  some  things  in  common 
between  the  study  of  science  in  school  (with  its  requirements 
to  master  and  use  what  may  be  learned  from  books,  experi- 
ments, and  the  experiences  of  life),  and  the  procedure  fol- 
lowed by  (a)  the  lawyer  who  undertakes  any  case  at  law; 
(6)  the  contractor  who  seeks  to  accomplish  any  large  job ; 
(c)  the  housewife  who  desires  to  spend  the  family  income  most 
advantageously. 


XII.  THE  FARM,  AND  OUR  FOOD  SUPPLIES 

THE   HEN1 

1.  TelLwhat  kind  of  fowls  you  keep  at  home  (if  any), 
and  their  distinguishing  characteristics  in  color,  build,  etc. 
How  could  you  identify  any  hens  of  yours  in  case  they  were 
to  get  with  a  neighbor's  fowls? 

2.  In  what  ways   are    chickens  hatched?      What   care 
must  be  given  little  chickens  ?     What  feed  is  used  for  them  ? 
What  other  provision  must  be  made  for  them  ?     What  food 
do  fowls  get  for  themselves  when  running  at  large  ? 

3.  Do  hens  chew  their  food  as  we  chew  ours  ?     How  is 
their  food  ground,  and  where?     Why  is  there  no  need  for 
horses  to  eat  gravel  and  bits  of  stone  ?     Does  a  hen  have  a 
tongue  ? 

4.  What  reason  is  there  to  believe  that  hens  can  hear? 
Where  in  the  head  are  a  hen's  ears  located  ?     Where  are  the 
nostrils  ?     How  does  a  hen  drink  ? 

5.  Do  hens  shut  their  eyes?     What  difference  in  their 
eyelids  from  ours  ?     (Watch  for  a  third  lid  that  moves  side- 
wise  over  the  eyeball.) 

6.  Why  do  not  hens  fly  as  freely  as  do  birds?    Where 
are  the  wings  attached  to  their  bodies  ?    Where  in  the  body 
are  the  muscles  for  flying  ? 

1  It  may  be  possible  to  have  in  the  room  for  a  few  days  one  or  more  fowls 
in  a  coop  such  as  used  at  poultry  shows. 

124 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         125 

7.  Of  what  use  to  the  hen  are  feathers  ?     Of  what  value 
are  feathers  for  household  uses  ?     How  do  hens  keep  clean  ? 
What  provision  is  made  for  new  plumage? 

8.  In  what  respects  is  the  foot  of  the  hen  different  from 
(a)  the  foot  of  a  horse ;   (6)  a  man's  foot  ?     How  many  toes 
on  a  hen's  foot?     To  what  uses  do  hens  put  their  claws? 
The  part  of  a  hen's  leg  above  the  toes  (the  part  that  is  cov- 
ered with  scales)  corresponds  to  what  part  of  the  human 
body  ?    Why  do  not  fowls  fall  off  when  asleep  on  perches  ? 

9.  What  is  the  purpose  of  (a)  the  comb ;   (b)  the  wattles  ? 
What  significance  in  their  changes  in  color  ? 

10.   Explain  differences  in  color  in  chicken  meat. 

EGGS 

1.   Remove  the  shell  from  an  egg  that  has  been  boiled 
in  some  "Easter  dye"  solution.     What  is  the  significance  of 

TH/MEFt  ALBUMEN^  ^^^          ^^^^^-GEf?M  SPOT,  OR  DISC. 

(»»<T*)       \x^>r^^c-  %T     «*  ***** 

TH/CKER  4LBVMEN- 
(WH/TE) 


CMLAZ*' 

CONCENTRIC 
MNER  MEMBRAMt  ^ 

^SHELL 
FIG.  57.  —  The  parts  of  an  egg. 

any  coloration  through  the  shell  ?  Recall  why  canned  goods 
do  not  spoil.  What  can  be  done  to  the  shells  to  keep  eggs 
for  a  long  time?  What  conditions  favor  the  decay  of  all 
animal  matter,  including  eggs? 


126     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

2.  Carefully  break  a  fresh  egg  into  a  clean  sauce  dish,  and 
note  (a)  the  germ,  and  its  location ;    (6)  the  light  and  dark 
parts  of  the  yolk;   (c)  the  chalaza  (ka-la'za). 

Examine  the  large  end  of  the  broken  shell  for  the  air 
space,  noting  the  membranes  inclosing  it.  Infer  if  air  can 
pass  through  these  membranes. 

3.  To  a  bit  of  the  shell  in  a  test  tube  add  some  strong  acid, 
and  describe  the  action.     Note  the  effect  of  any  escaping 
gas  upon  a  drop  of  limewater. 

4.  To  a  small  piece  of  boiled  white  of  egg  in  a  dish  add 
strong  nitric  acid;    note  any  color  change  as  the  acid  is 
warmed  a  little. 

Pour  off  the  acid,  rinse  with  water,  and  then  add  strong 
ammonia  water.  Describe  any  further  color  change. 

These  steps  and  their  results  illustrate  tests  for  the  im- 
portant class  of  "food  substances  known  as  protein  (pro'te-m). 
The  albumen  of  egg  is  but  one  of  these.  They  are  the  tissue- 
building  material  of  our  foods. 

5.  Observe  closely,  and  state  the  results,  as  the  teacher 
adds  alcohol  slowly  to  a  little  uncooked  white  of  egg  in  a 
test  tube,  shaking  the  tube  from  time  to  time. 

POULTRY   KEEPING 

1.  Aside  from  profit  what  are  good  reasons  for  keeping 
a  few  fowls  at  one*s  home?  Name  some  classes  of  people 
other  than  farmers  who  can  profitably  engage  in  the  poultry 
business  on  a  small  scale  ?  What  traits  of  character  are  quite 
essential  in  one  who  is  to  make  a  success  of  poultry  raising  ? 
What  is  a  safe  course  for  any  one  beginning  to  keep  poultry  ? 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         127 

2.  Give  arguments  for  and  against  making  poultry  rais- 
ing a  sole  business.     What  are  the  advantages  of  making  it 
incidental  to  general  farming  ? 

3.  What  are  the  advantages  and  disadvantages  in  keep- 
ing pure-bred  stock  ? 

4.  What  is  the  importance  of  keeping  the  poultry  ac- 
counts in  a  businesslike  way? 


FIG.  58.  —  Cross  section  of  a  poultry  house. 

5.  What  may  be  considered   a  good  site  for  a  chicken 
house  with  reference  to  (a)  character  of  the  ground ;  (6)  near- 
ness to  the  barn  and  stables?    What  preferably  is  (a)  the 
kind  of  foundation  for  the  house ;    (6)  the  nature  of  the  floor, 
and  the  care  to  be  given  it?     What  covering  should  be  pro- 
vided for  the  floor  when  it  is  of  cement  ? 

6.  What  provisions  should  be  made  (a)  for  keeping  the 
chicken  house  clean ;  (6)  for  extermination  of  lice  and  mites  ? 
What  uses  have  whitewash  and  coal-tar  wash?  How  is 
"  whitewash  "  prepared  ? 


128     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

7.  Discuss  arrangements  for  warmth,  for  light,  and  for 
the   ventilation   of   the   chicken   house.     What   provisions 
should  be  made  for  exercise  by  the  fowls,  and  for  dust  baths  ? 
Where  should  nests  be  placed,  and  what  schemes  may  be 
employed  to  keep  them  clean? 

8.  Make  a  diagram  in  some  detail  showing  the  interior 
of  a  chicken  house.     At  about  what  cost  may  a  substantial 
house  for  a  flock  of  twenty  fowls  be  built? 

9.  In  the  hatching  of  chickens,  what  advantages  (a)  in 
setting  hens;    (b)  from  use  of  incubators?     Describe  in  a 
general  way  the  construction  of  an  incubator. 

10.  Where  incubators  are  used,  (a)  what  time  is  required 
for  hatching  the  eggs ;  (b)  what  per  cent  of  the  eggs  are  likely 
to  hatch  under  favorable  conditions;    (c)  what  care  should 
be  observed  as  to  the  temperature  maintained,  the  supply  of 
moisture  for  the  eggs,  and  their  turning  and  cooling  ? 

11.  How  is  the  fertility  of  eggs  to  be  determined  after 
they  have  been  a  few  days  in  the  incubator  ?     How  soon  can 
this  be  done  ? 

12.  What  arrangement  serves  as  a  chick  nursery  within 
the    incubator?     Of    brooders,    state    (a)    their    purpose; 
(b)  the  manner  of  their  construction ;    (c)  the  rate  of  reduc- 
tion of  temperature  in  them  ;   (d)  their  period  of  use. 

13.  How  often  should  little  chicks  be  fed,  and  how  much 
at  a  time  ? 

14.  In  general,  what  care  should  be  gjven  grown  fowls? 
State  the  kind,  and  the  relative  cost  of  foodstuffs  for  hens. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         129 

How  can  green  feed  be  provided  (a)  in  winter ;  (6)  as  pas- 
turage in  summer?  How  may  exercise  for  the  fowls  be 
secured  through  a  feeding  scheme?  What  provision  may 
be  made  for  "picking  material"?  What  provision  must 
be  made  for  drinking  vessels,  and  for  a  water  supply  ? 

15.  In  the  marketing  of  poultry  and  eggs  (a)  what  advan- 
tage is  there  in  direct  sales  to  the  consumer ;    (6)  what  care 
should  be  exercised  in  grading  the  quality  of  the  product 
sold? 

16.  Name   some   diseases   to   which   fowls   are   subject. 
What  preventive  measures  should  be  employed? 

17.  State  the  educational  values  possible  for  boys  and 
girls  (a)  from  school  courses  in  poultry  keeping ;  (6)  from  the 
care  of  poultry  at  home.      What  relation  may  this  school 
instruction  in  poultry  keeping  have  (a)  to  community  life ; 
(6)  to  exhibits  at  the  schoolhouse,  and  at  Fairs? 

THE   HORSE 

1.  Do  you  have  a  horse  at  home  ?     If  so,  why  do  you 
keep  it  ?     (If  not,  why  not  ?) 

2.  If  a  horse  should  get  out  of  the  barn  some  night  and 
go  away,  how  could  the  owner  know  it  as  his  horse  when  it 
was  found  ?     In  what  other  ways  might  it  be  identified  ? 

3.  Why  is  it  best  to  keep  away  from  strange  horses? 
How  does  your  horse  behave  toward  you?    Why  so?     In 
driving,  how  do  horses  sometimes  misbehave  ?    What  makes 
them  do  this?    Why  do  horses  so  seldom  misbehave? 

4.  Who  else  that  you  know  keeps  a  horse?    For  what 
use?    What  kind  of  horse  best  serves  (a)  the  man  who 
delivers  heavy  loads  of  coal;    (b)  the  livery  man  whose 


130     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

horses  must  go  many  miles  a  day  ?    Wherein  do  ponies  differ 
from  horses  ? 

5%.  What  do  you  feed  your  horse?  How  often  do  you 
feed  it,  and  how  much  at  a  time?  What  changes  of  feed 
are  sometimes  made  (a)  winter  and  summer;  (6)  when  the 
horse  is  working  hard  and  when  doing  nothing?  WThat  are 
the  present  market  prices  (a)  of  hay;  (6)  of  oats?  W7hat 
other  care  should  be  given  a  horse  besides  feeding  and  water- 
ing it  ?  Why  is  this  needful  ?  What  is  true  of  the  amount 
of  feed  a  horse  needs  if  kept  in  a  warm  rather  than  a  cold 
stable  in .  winter  ?  What  care  should  be  given  a  horse  if 
hitched  outside  on  a  very  cold  day  in  winter  ?  WThy  should 
a  horse  not  be  driven  fast  on  cold  days? 

6.  When  you  drive  your  horse,  how  does  it  know  where 
to  go?    Why  do  you  not  need  to  have  bits  in  your  mouth 
that  you  may  go  where  you  ought  ?     How  does  a  horse  know 
when  to  stop?     To  what  part  of  the  harness  are  the  lines 
fastened  ?     Why  should  a  driver  not  jerk  hard  on  the  lines  ? 
In  cold  weather,  how  may  the  bits  cause  pain  to  the  horse  ? 

7.  What  is  the  checkrein  of  a  harness?    Hold  your  head 
for  a  little  time  as  the  horse  has  to  hold  its  head  when  checked 
up  high.     What  is  the  feeling  you  have? 

8.  Of  what  use  in  the  harness  are  (a)  tugs ;  (b)  holdbacks  ? 
Against  which  part  of  the  body  does  the  harness  rub  most 
when  the  horse  is  drawing  a  heavy  load?    What  care  is 
necessary  because  of  this? 

9.  How  does   a   horse   show  (a)   that  he  is  impatient; 
(6)  that  he  is  tired ;   (c)  that  he  cares  for  you ;   (d)  that  he  is 
afraid  of  you ;    (e)  that  he  is  .afraid  of  something  by  the 
way  ?    When  only  should  a  whipping  be  given  a  horse  ? 


THE   FARM,   AND   OUR   FOOD   SUPPLIES        131 

10.  Describe  as  well  as  you  can  the  shape  of  the  horse's 
head  as  compared  with  your  own.     Make  on  your  paper  a 
drawing  of  a  horse's  head. 

11.  Where  in  its  head  are  the  eyes  ?     Of  what  advantage 
to  the  horse  is  this  location? 

12.  Where  are  the  ears  placed  ?     What  are  some  advan- 
tages from  this  position  ? 


FIG.  59.  —  Skeleton  of  a  horse.     Note  especially  the  arrangement  of  the 
bones  in  foreleg  and  hind  leg. 

13.  Watch  the  horse  eat,  and  see  how  it  gets  food  into  its 
mouth.     Why  do  we  not  need  to  eat  in  the  same  manner? 

14.  Watch  a  horse  drink,  and  then  a  hen.     What  about 
a  hen's  mouth  is  different  from  the  mouth  of  a  horse  or  of  a 
man? 


132     LABORATORY    LESSONS   IN   GENERAL   SCIENCE 

15.  What    is    peculiar    about    a    horse's    foot,    and   by 
what   name    is  it   called?    Why    do    we   have  iron  shoes 
on   the    feet    of  a  horse   (a)   in  winter;    (6)   in  summer? 
What  harm  results  from    keeping  the  same  shoes  on  too 
long?    To  what   part  of   our  foot  does  the   horse's   hoof 
correspond  ? 

16.  Show  in  a  sketch  of  the  hind  leg  of  the  horse  where 
the  joints1  are  that  correspond  (a)  to  our  ankle;   (6)  to  our 
knee ;   (c)  to  our  hip. 

17.  On  what  parts  of  the  body  of  the  horse  is  the  hair  of 
unusual  length,  and  what  are  the  names  given  these  different 
long  growths  ?     Of  what  use  to  the  horse  is  the  tail  ?     What 
care  should  be  given  the  hair  and  skin  of  the  horse  ?     What 
changes  have  you  noted  in  the  hair  of  the  horse  at  different 
seasons  ? 

COWS  AND  THE  DAIRY  INDUSTRY 

1.  Name  several  considerations  that  enter  into  the  mar- 
ket value  of  a  cow  for  dairy  use.     About  what  is  the  present 
value  in  your  community  (a)  of  common  "  grade"  cows; 
(6)  of  "full-blooded"  stock? 

2.  How  in  general  does  care  of  the  cow  compare  with 
that  of  the  horse  in  matters  of  food,  drink,  shelter,  and 
kind  treatment  ? 

3.  In  what  respects  is  the  foot  of  the  cow  unlike  that 
of   the   horse?     What  is  a    noticeable  difference    in   their 
tails? 

1  Notice  horses  from  time  to  time  till  you  can  locate  the  place  of  each  such 
joint.    Note  the  places  of  the  corresponding  joints  in  the  foreleg. 


THE   FARM,    AND   OUR   FOOD   SUPPLIES         133 


4.  Where  are  the  horns  with  reference  to  the  ears?     Of 
what  use  are  the  horns  ?     Why  is  dehorning  of  cows  so  gen- 
eral in  dairies? 

5.  How  many  teeth  has   a    cow  in   each   jaw?    What 
takes  the  place  of  the  front  teeth  in  the  upper  jaw?     Does 


FIG.  60.  —  Cuts  of  meat  in  a  beef  animal. 


1.  Neck 

2.  Chuck 

3.  Ribs 

4.  Shoulder 

5.  Fore  shank 


6.  Brisket 

7.  Cross  ribs 

8.  Plate 

9.  Navel 
10.  Loin 


11.  Flank 

12.  Rump 

13.  Round 

14.  2d  cut  round 

15.  Hind  shank 


the  cow  in  grazing  bite  off  grass  as  does  the  horse  ?  What  is 
peculiar  about  a  cow's  way  of  eating  hay  and  grass,  and  what 
is  meant  by  a  cow's  "chewing  the  cud"? 

6.  Describe  the  manner  in  which  a  cow  lies  down  and 
gets  up,  comparing  it  with  the  way  of  a  horse. 

7.  Make  a  list  of  the  various  cuts  of  beef  bought  at  the 
butcher  shop,  with  the  name  of  the  part  of  the  animal  whence 
each  is  obtained. 

8.  State  briefly  the  processes  of  changing  the  hides  of 
cows  into  leather.    Explain  why  leather  does  not  decay. 


134    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 


9.   What  are  various  uses  for  (a)  cow's  hair;    (b)  the 
horns ;    (c)  the  blood ;    (d)  the  bones ;    (e)  the  fat  ? 

10.  Name  at  least  two  different  breeds  of  cows,  and  state 
in  what  respects  they  differ  in  (a)  size ;   (6)  color ;   (c)  quan- 
tity and  quality  of  milk  given ;   (d)  beef  production. 

11.  Where  a  cow  is  kept  for  profitable  milk  production, 
what  must  be  true  (a)  of  the  quantity  and  quality  of  feed ; 
(b)  of  the  water  supply;    (c)  of  regularity  in  feeding  and 
milking ;   (d)  of  definite  knowledge  of  the  income  and  outlay 
for  each  animal  ? 

12.  Of  what  advantage  is  the  use  of  the  cream  separator 
in  dairying  as  to  (a)  amount  of  cream  taken  from  the  milk ; 
(6)  labor  involved  in  the  care  of  milk?     In  what  ways  has 
the  general  use  of  cream  separators  largely  changed  the 

industry     of     butter- 
j  t  j  j  making  ?      What   use 

I  1  L-L 1  1  does  the  farmer  make 
of  the  milk  from 
which  the  butter-fat 
has  been  separated? 

13.  What  sections 
of  country  are  espe- 
cially favorable  for 

FIG.  61.  —  Clean  milk  requires  precautions  at    dairying      as      regards 

(a)   general  character 

of  the  country  for  tillage ;  (b)  price  of  land  per  acre ;  (c)  dis- 
tribution of  rainfall  throughout  the  grazing  season ;  (d)  near- 
ness to  town  and  city  as  markets  ? 

14.   Even  where  milk  is  sold  in  stoppered  bottles,  how  may 
the  consumer  be  endangered  by  carelessness  and  ignorance 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         135 

(a)  in  the  care  of  the  bottles ;  (6)  at  milking  time ;  (c)  in  the 
stabling  of  the  cows  ? 

15.  Where  only  the  butter-fat  of  milk  is  sold,  what  ani- 
mals may  be  raised  to  add  to  the  profits  of  the  dairy  busi- 
ness? Why  should  there  be  a  greater  and  ever  increasing 
fertility  for  the  dairy  farm  in  contrast  with  the  very  common 
impoverishment  of  farms  cropped  year  after  year  with  corn, 
small  grains,  cotton,  etc.  ? 

SOME   FOODSTUFFS 

1.  Melt  (or  soften)  a  little  butter,  and  put  a  drop  of  it 
on  a  piece  of  glazed  paper  (letter  paper) .     What  appearance 
is  given  the  paper?     What  class  of  substances  gives  similar 
results  ?     What  is  the  nature  of  butter  ?     Describe  the  steps 
in  butter-making.     Of  what  use  is  butter  as  a  foodstuff? 
What  are  good  reasons  for  its  use  with  bread? 

2.  What  is  oleomargarine?    What  are  the  claims  for 
and  against  its  use  as  a  foodstuff?     Why  is  there  a  heavy 
government  tax  upon  oleomargarine  ?     What  is  "  cottolene  " 
and  what  are  its  uses  ?     Name  other  like  compounds  having 
a  similar  use. 

3.  What  conditions  of  temperature  and  of  acidity  are 
favorable  for  the  best  results  in  churning  ?     What  is  (a)  but- 
termilk ;   (6)  lactone  ?     What  is  renovated  butter,  and  why 
is  it  less  in  price  ? 

4.  Observe  very  closely  the  results  as  the  teacher  per- 
forms the  following  experiments,  and  tell  in  each  case  what 
is  the  distinction  shown  between  real  butter  and  its  imi- 
tations :  — 


136    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

(a)  In  a  spoon  heat  in  turn  small  pieces  of  each  substance, 
stirring  them  with  a  match  stick  as  they  boil.  Note  which 
boils  with  much  foam  and  which  with  much  sputtering. 

(6)  Note  the  differences  in  results  as  the  substances  are 
tested  separately  as  follows :  Put  a  small  lump  into  a  test 
tube  one  fourth  full  of  milk,  and  heat  till  the  lump  is  melted ; 
then  stir  the  liquid  with  a  long  splinter  of  wood,  cooling  the 
tube  under  the  faucet  till  the  fat  hardens.  In  one  case 
the  fat  should  collect  in  a  mass  that  can  be  removed  on  the 
splint,  and  in  the  other  cases  it  remains  scattered  in  gran- 
ules throughout  the  milk. 

Summarize  the  results  by  which  any  one  of  these  sub- 
stances may  be  identified  with  a  reasonable  degree  of  cer- 
tainty. 

5.  What    per  cent    of    butter-fat  should  be  present  in 
milk  ?     What  per  cent  of  milk  is  water  ?     What  preservatives 
have  been  most  commonly  used  in  milk?     Wherein  is  the 
harm?     What  causes  the  souring  of  milk  by  natural  pro- 
cesses?    How  is  this  ordinarily  delayed  in  household  uses? 

6.  What  is  (a)  condensed  milk,  and  its  especial  worth; 
(6)  sterilized  milk;    (c)  Pasteurized  milk? 

7.  Observe  results  closely,  and  state  what  is  noted  as 
the  teacher  (a)  adds  to  one  fourth  test  tube  of  milk  a  little 
vinegar,  warming  and  shaking  till  separation  of  curd  and 
whey  occurs;    (6)  tests  some  of  the  curd  with  nitric  acid, 
and  then  with  ammonia  solution,  for  protein  food  material. 

8.  Describe   briefly   the    making    of    cheese.      Mention 
various  kinds  of  cheese,  and  the  differences  in  their  manu- 
facture. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES        137 

0.  Name  three  food  constituents  of  milk.  By  what 
means  may  each  be  separated  from  the  others?  Discuss 
milk  as  a  perfect  food  for  infants. 

10.  Distinguish    between    (a)    suet,    tallow,    and    lard ; 
(6)  veal,  mutton,  and  pork.      What  are  the  chief  reasons  for 
cooking  meat  ? 

11.  What  different  means  are  employed  to  prevent  decay 
in  uncooked  meats?     In  sausage  made  up  in  quantity  and 
exposed  for  sale,  (a)  what  preservative  is  sometimes  used; 
(6)  what  is  used  as  a  "filler"  ? 

12.  What  great  advantages  affecting  our  food  supply  have 
resulted  from  the  canning  of  meats  and  fish?     Why  are 
there  so  many  cases  of  ptomaine  poisoning  from  chicken  or 
salmon  salad?     When  a  can  of  meat  is  opened,  what  pre- 
cautions should  be  taken  before  the  meat  is  eaten?    What 
is  the  nature  of  ptomaine  poisoning? 

13.  What  are  the  chief  food  constituents  of  lean  meat 
(muscular    tissue)  ?     What    are    their    digestive    solvents  ? 
What  are  peptones?    What  is  the  nature  of  the  digestion 
of  fats? 

14.  What  is  the  chemical  nature  of  bone?    Which  are 
the    chief    foodstuffs    providing  •  bone-building    material  ? 
How  may  the  relative  weight  proportions  of  animal  and 
mineral  material  in  bones  be   quite  readily  determined? 
What  use  is  made  by  the  body  of  the  "lime"  in  water? 

15.  From  what  is  soap  made,  and  how  ?    Give  the  nature 
of  glycerine,  and  its  uses. 


138     LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

LESSONS   ON  CORN 

(a)  Corn  in  the  Field 1 

1.  Measure  the  distance  between  hills  of  corn  in  a  row, 
and  then  calculate  the  number  of  them  in  a  row  16  rods 
long.     Measure  the  distance  from  row  to  row,  and  calcu- 
late the  number  of  rows  in  a  width  of  10  rods.      Calculate 
the  number  of  hills  in  an  acre  (160  square  rods).     With  four 
kernels  per  hill,  how  many  kernels  are  needed  to  plant  an 
acre? 

2.  Count  the  number  of  stalks  in  a  plot  nine  hills  each 
way.      With  three  stalks  2  to  the  hill,  how  many  stalks 
should  there  be  in  the  plot  ?     What  is  the  per  cent  of  short- 
age (or  excess)  ? 

3.  Count  the  number  of  ears  in  the  plot  of  81  hills.     With 
one  ear  on  each  of  three  stalks  2  per  hill,  how  many  ears  should 
there  have  been?     What  per  cent  of  shortage  (or  excess)  is 
found?     How  many  ears  shortage  (or  excess)   is  this  per 
acre?    How  many  bushels  of  ears  in  this,  taking  100  ears 
per  bushel  as  an  average  ?    How  much  shelled  corn  ?    What 
value  has  this  amount  of  corn  at  the  market  price? 

4.  About  what  is  the  average  height  of  the  stalks?     If 
any  are  broken  down,  at  what  places  with  reference  to  the 
joints  (nodes)  are  the  breaks?     Where  are  the  leaves  at- 
tached to  the  stalks?     What  is  the  purpose  of  joints  in  the 
framework  of  our  bodies?    What  is  told  of  the  corn  plant 
by  the  varying  lengths  between  joints  ? 

1  In  the  autumn. 

2  Use  four  per  hill  for  those  varieties  having  relatively  short  stalks  and 
small  ears. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES        139 


Struc- 
ture of  corn- 
stalk. 


5.  Cut  a  stalk  crosswise,  and  notice  where  the  woody 
fibers  are  closest  together.     Slit  a  stalk  lengthwise,  and  com- 
pare the  structure  at  the  nodes  and  between 

them  (inter nodes) .  What  is  true  of  the  rela- 
tive size  and  strength  of  a  stalk  at  the  joints 
and  between  them?  What  connection  is 
there  between  the  woody  fibers  of  the  stalk 
and  the  fibers  (veins)  in  the  leaves?  How 
are  the  fibers  arranged  in  the  stalk  relative  F 
to  one  another?  How  is  it  in  the  leaves? 
What  diameter  (and  circumference)  has  a 
stalk  of  average  size  two  feet  above  the  ground? 

6.  About  how  high  on  the  stalks  are  the  ears?     What  is 
the  length  of  the  ear  stem  ?     What  would  be  one  disadvan- 
tage in  having  (a)  the  ears  too  high  up ;   (b)  the  ear  stems  too 
long?     Where  are  the  ears  with  reference  to  the  leaves? 
What  change  is  there  in  the  shape  of  the  stalk  where  the  ear 
is?     How  are  the  leaves  arranged  on  the  stalk?     When  do 
com  leaves  curl  ?  '  What  is  the  cause  of  this  curling  ?     What 
is  the  advantage  to  the  plant  in  this  ? 

7.  Gather  one  of  the  -largest  and  one  of  the  smallest  of  the 
ears.     What  is  true  of  the  size  of  the  stalk  on  which  each 
grew  ?     What  is  the  number  of  stalks  in  each  of  these  hills  ? 
What  seems  a*  good  number  of  stalks  for  a  hill,  and  what  is 
the  best  relative  size  of  stalk? 

8.  Uproot  one  or  more  hills,  and  describe  the  general  char- 
acter of  the  roots.     What  special  use  have  the  "air  roots" 
of  the  corn?    To  about  what  depth  did  the  corn  roots 
grow?    What  relation  has  this  to  the  depth  to  which  the 
soil  should  have  been  plowed?     How  far  sidewise  did  the 


140    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 


roots  reach  out?  What  bearing  has 
this  on  a  late  cultivation  of  the  crop  ? 
9.  Select  a  good  ear  and  carefully 
remove  its  husks.  If  the  stem  bear- 
ing the  ear  were  greatly  extended 
outward,  to  what  would  these  husks 
on  this  new  stalk  correspond  ?  Note 
to  what  each  of  the  threadlike  silks 
is  attached  at  its  inner  end.  Observe 
in  other  ears  whether  the  silks  extend 
outward  beyond  the  husks.  Where 
on  the  cornstalk  were  other  blossoms 
that  bore  stamens  and  an  abundance 
of  pollen  grains?  What  is  true  of 
the  times  of  appearance  of  silks  and 
"tassels"?  How  will  it  affect  the 
crop  if  the  weather  at  such  a  time 
FIG.  63.  —  Roots  of  the  is  very  hot  and  dry,  or  too  wet  and 

corn  plant.  ,  ,  Q 

cold? 

(b)  A  Study  of  Ears  of  Corn 

1.  Count  the  number  of  rows  of  kernels  on  an  ear  of  me- 
dium size,  and  the  number  of  kernels  in  one  row.  Calculate 
the  number  of  kernels  per  ear.  How  many  ears  are  needed 
to  plant  an  acre?  (See  paragraph  1,  Corn  in  the  Field.) 
How  many  bushels?  (See  paragraph  3.)  Of  the  ear  that 
you  examine,  state  (a)  if  the  kernels  fill  the  ear  entirely 
over  the  tip ;  (b)  if  there  are  any  places  where  kernels  are 
missing ;  (c)  if  the  base  of  the  ear  is  large  and  well  filled  out. 
State  whether  the  kernels  are  crowded  close  together  on  the 
cob,  and  whether  they  are  of  uniform  size  and  shape. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         141 

2.  Choosing  what  you  consider  the  best  ear,  find  the  cir- 
cumference at  one  third  its  length  from  the  base.  Calcu- 
late the  ratio  of  this  circumference  to  the  length  of  the  ear. 
Break  the  ear  at  about  its  middle  and  determine  the  ratio 
(a)  of  the  diameter  of  the  cob  to  the  diameter  of  the  ear; 


FIG.  64.  —  Specimen  ears  of  different  varieties  of  corn. 

(b)  of  the  area  of  the  broken  end  of  the  cob  to  the  broken  end 
of  the  ear.1 

3.  Get  a  good  ear  of  cured  (old)  corn  and  find  the  ratio  of 
the  weight  of  the  cob  to  the  weight  of  the  ear  before  it  was 
shelled. 

4.  Somewhat  at  length,  and  very  specifically,  state  the 
characteristics  of  the  best  ears  of  corn. 

1  The  areas  of  circles  are  to  each  other  as  the  squares  of  their  diameters. 


142    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

5.  What  advantage  is  there  (if  any)  in  having  the  ker- 
nels wedge-shaped?     State  if  there  is  any  dent  in  the  large 
end  of  the  kernel.     What  differences  are  there  in  the  sides 
of  a  kernel  ?     With  a  knife  remove  the  thin  outer  coating 
of  a  kernel  (its  hull).     Note  where  the  color  of  the  kernel 
seems  to  be  lodged.     At  what  place  in  the  hull  is  a  hole 
found?     What  is  its  probable  purpose? 

6.  Examine  some  kernels  that  have  been  in  water  for  two 
or  three  days,  and  away  from  the  light.     What  change  has 
occurred  in  the  size  of  the  kernel,  and  of  the  groove  in  its 
side?     Having  removed  the  hulls,  cut  some  of  the  kernels 
lengthwise  along  the  groove,  and  others  lengthwise   but  at 
right  angles  to  it.     Observe  the  little  embryo  in  each  case. 
The  large  portion  of  the  kernel  surrounding  the  embryo  is 
the  endosperm. 

7.  Put  several  of  the  soaked  kernels  between  blotting 
papers  kept  moist  in  a  warm  room  for  several  days;     Ex- 
amine the  embryo,  and  infer  what  it  is  likely  to  become. 
Distinguish  between  its  plumule  and  its  radicle  (root).     Dis- 
tinguish any  parts  of  the  plumule,  and  of  the  root.     Observe 
any  hairlike  rootlets,  and  tell  where  they  are.      The  change 
which  has  taken  place  in  the  kernels  is  called  germination. 
After  corn  is  planted,  to  what  extent  can  conditions  for 
germination  be  controlled  ?     About  how  early  in  the  Spring 
is  it  safe  to  plant  corn  in  your  section  of  country  ? 

8.  Fill  a  glass  fruit  jar  with  mellow  soil  that  is  somewhat 
moist  (but  not  water-soaked).     Push  down  into  the  soil 
next  the  sides  of  the  jar  where  they  can  be  seen  several 
kernels  that  have  been  soaked  for  three  days.     Have  them 
at  different  depths  below  surface.     Keep  the  soil  just  moist, 


THE  FARM,   AND   OUR  FOOD  SUPPLIES        143 

the  jar  covered  with  a  black  cloth,  and  all  conditions  for 
germination  favorable.  Examine  the  jar  daily  till  the  best 
depths  for  planting  seem  apparent.  Note  any  marked  tend- 
ency in  directions  of  growth  of  the  plumule  and  of  the  rad- 


Fio.  65.  —  Results  of  planting  at  different  depths  (in  inches). 

icle.  What  is  the  number  of  leaves  when  the  young  plant 
comes  through  the  soil?  What  condition  of  the  soil  favors 
the  outward  growth  of  root  and  plumule?  What  prepara- 
tion of  the  soil  is  desirable  before  planting  corn  for  a  crop  ? 
What  purpose  is  there  in  the  cultivation  of  the  soil  at  its 
surface  only  during  the  growing  season  ? 


144    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

(c)  Corn  Raising  as  an  Industry 

1.  What  variety  of   corn  is   most   commonly  raised  in 
your  section  of  country?     Name  some  other  varieties. 

2.  Tell  how  seed  corn  for  another  season  should  be  se- 
lected.   How  should  it  be  cared  for  after  it  has  been  gathered  ? 
How  is  seed  corn  tested  for  its  powers  of  germination  ? 

3.  Describe  somewhat  at  length  the  manner  of  gathering 
a  crop  of  corn.     What  determines  the  time  for  beginning  its 
harvest?    About  how  long  a  time  is  it  from  planting  till 
the  crop  is  ripe  enough  to  be  gathered?    Why  is  the  new 
crop  often  stored  for  a  time  in  cribs  ? 

4.  What  machinery  is  employed  in  raising  a  corn  crop? 
In  harvesting  it  ?     In  marketing  it  ?     In  general,  is  the  cost 
per  acre  of  raising  a  large  yield  of  corn  likely  to  be  much 
more  than  for  a  small  yield  ?    Why  so  ?    What  expense  items 
are  likely  to  be  greater?    What  are  several  advantages  to 
the  farmer  in  feeding  his  corn  on  the  farm  rather  than  sell- 
ing it  ?    As  land  values  and  the  cost  of  labor  increase,  involv- 
ing need  of  larger  capital  to  carry  on  successful  farming, 
what  is  likely  to  become  more  and  more  true  of  the  degree 
of  business  ability  necessary  to  make  farming  a  paying  in- 
dustry ? 

6.  Name  a  large  number  of  the  products  of  packing 
houses  where  corn-fed  cattle  and  hogs  are  marketed.  How 
very  largely  is  this  livestock  brought  to  the  packing  houses  ? 
How  are  the  packing  house  products  distributed  to  con- 
sumers? What  would  be  the  effect  upon  the  number  of 
men  employed  in  these  fields  of  industry  if  there  should  be 
a  failure  in  the  corn  crop  for  a  year  or  two?  What  would 


THE   FARM,   AND   OUR   FOOD   SUPPLIES        145 


146    LABORATORY   LESSONS  IN   GENERAL    SCIENCE 

be  the  effect  upon  the  manufacture  and  sale  of  farm  imple- 
ments? Upon  the  purchasing  ability  of  farmers  for  sup- 
plies? Upon  merchants  and  manufacturers?  Upon  living 
expenses  for  the  people  of  the  country? 

6.  From  what  you  are  able  to  learn  by  a  visit  to  the  near- 
est canning  factory  (or  from  books)  briefly  describe  the  steps 
in  the  processes  of  canning  corn  from  the  time  the  corn  is 
delivered  at  the  factory  till  the  cans  are  packed  in  boxes  for 
shipment. 

7.  Of  what  use  on  the  farm  is  a  silo  f     Explain  why  great 
care  must  be  exercised  in  its  construction.     What  fodder  is 
used  for  filling  silos  ?     Of  what  special  advantage  to  the  dairy- 
man is  the  use  of  ensilage?     What  prevents  the  rotting  of 
the  material  stored  in  the  silo? 

8.  Briefly  retell  the  steps  in  the  manufacture  of  corn 
starch  as  described  in  some  reference  book.     Name  some 
uses  of  starch  in  the  home. 

9.  What  is  glucose  f   How  is  it  made  ?   What  uses  has  it  ? 
10.   Name  some  of  the  corn  breakfast  foods.     In  general, 

how  are  they  prepared?  In  what  other  forms  is  corn  used 
as  a  food  for  men? 

FRUIT    AND  APPLE  RAISING  AS  AN  INDUSTRY 

1.  In  a  column  write  a  list  of  the  various  fresh  fruits  that 
may  be  purchased  at  certain  times  during  the  year  at  fruit 
stands  and  grocery  stores  in  your  home  town.  Underscore 
the  names  of  those  grown  in  your  immediate  vicinity.  After 
each  of  the  names  of  the  others  write  the  country  or  section 
where  it  is  grown  for  market.  In  a  third  column  write  the 
prevailing  price  for  each  fruit  in  season. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         147 

2.  Explain  how  it  is  possible  to  ship  and  market  in  good 
condition  such  perishable  fruits  as  (a)  bananas ;   (6)  berries. 
Name  conditions  that  must  be  observed  by  shippers  and 
fruit  dealers  generally  so  that  a  ready  market  shall  be  found 
for  their  fruit.     Compare  the  keeping  qualities  of  the  orange 
and  of  other  fruits  in  market.     Account  for  any  differences. 

3.  If  we  accept  the  definition  that  a  fruit  is  the  ripened 
product  of  plant  growth  bearing  the  seeds  of  that  plant, 
what  so-called  vegetables  come  into  the  list  of  fruits?     Of 
what  use  are  the  seeds  produced  by  plants  ?     Describe  ways 
in  which  various  plants  secure  the  dispersion  of  their  seeds. 
What  is  true  with  regard  to  seeds  in  the  banana,  and  in  some 
oranges?     Describe  the  propagation  of  these  fruits.     Make 
a  list  of  a  half  dozen  plants  that  could  be  propagated  without 
seed  production  by  them,  and  state  how  this  might  be  accom- 
plished.    What  would  be  true  of  plants  generally  if  no  seeds 
were  to  be  grown  for  several  seasons  in  succession?     What 
effect  on  mankind  would  failure  of  plants  to  produce  seeds 
have  ?     Give  some  examples  to  show  this. 

4.  Fresh  apples  when  cut  and  exposed  to  the  air  soon  turn 
brown.     Why  are  evaporated  apples  so  white?     What  is 
true  of  the  relative  degree  of  preservation  of  the  flavor  of 
apples  when  dried  and  when  canned  ?     About  what  per  cent 
of  an  apple  is  water?     Account  for  the  shriveling  of  apples 
kept  in  a  warm  basement. 

5.  About  what  should  be  the  age  and  size  of  trees  to  set 
out  for  an  apple  orchard?     What  is  the  cost  of  standard 
varieties  of  such  trees  at  the  nearest  reliable  nursery  ?     How 
many  years  before  apple  trees  are  likely  to  bear  fruit  ? 


148     LABORATORY   LESSONS   IN   GENERAL  SCIENCE 


6.  What  does  the  nurseryman  mean  by  "seedlings"? 
What  has  to  be  done  with  them  in  order  to  be  sure  of  the  kind 
of  apple  borne  by  the  tree  when  grown  ?  Describe  this  pro- 
cess. Account  for  the  different  varieties  of  apples.  How 

have  these  been  improved? 
Why  are  crab  apple  trees 
often  used  as  the  "stock" 
into  which  the  scions  of  im- 
proved varieties  are  grafted  ? 

7.  Describe  a  suitable 
preparation  of  ground  for 
setting  out  an  orchard.  What 
care  must  be  exercised  with 
the  young  trees  at  the  time 
of  transplanting?  What  is 
the  best  time  of  year  for 
setting  out  apple  trees  in 
your  section  of  country? 
About  how  far  apart  should  apple  trees  be  set?  Why  not 
closer  ?  Calculate  the  number  of  trees  per  acre  (a  strip  ten 
rods  wide  by  sixteen  rods  long).  In  what  ways  may  profit- 
able use  of  this  ground  be  made  in  the  years  before  the  trees 
are  large  enough  to  bear  fruit  freely  ? 

8.  About  how  many  bushels  of  marketable  apples  may 
be  considered  a  satisfactory  yield  for  a  tree  in  full  bearing? 
That  will  be  how  many  bushels  per  acre?  At  retail  prices 
on  the  local  market  calculate  the  value  of  the  crop  per  acre. 
After  apples  are  sold  from  the  orchard,  what  charges  increase 
their  cost  to  consumers  ? 


FIG.  67.  —  Grafting  fruit  trees. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         149 

9.  About  what  time  of  year  do  apple  trees  blossom? 
What  course  is  followed  in  large  orchards  to  prevent  loss  of 
the  season's  crop  by  a  late  freeze  in  the  spring?  About 
when  are  the  earliest  varieties  of  apples  on  the  market  for 
eating?  How  is  it  that  these  kinds  ripen  so  much  earlier 
than  some  other  kinds  ? 

10.  Does  every  blossom  of  the  springtime  yield  an  apple 
in  autumn  ?     If  this  were  so,  what  would  be  the  results  (a)  in 
the  size  and  quality  of  the  apples;    (b)  for  the  tree  itself? 
What  course  is  pursued  by  some  growers  to  get  exceptionally 
fine  fruit  ?     Why  is  this  not  done  by  all  apple  raisers  ? 

11.  What  special  care  must  be  exercised  in  harvesting 
apples?    Why  are  boxes  preferred  to  barrels  for  the  larger, 
finer  fruit?    Why  does  wrapping  each  apple  separately  in 
paper  aid  materially  in  its  keeping  qualities?     Explain  the 
nature  of  rot  in  apples.     What  is  nature's  protection  of  the 
apple  from  decay?    Why  do  apples  graded  as  to  size  and 
appearance  sell  more  readily  in  market  ?     What  is  true  of  the 
relative  selling  prices  of  these  apples  and  of  others  marketed 
by  the  barrel  ?    When  apples  are  to  be  kept  for  any  length 
of  time,  what  should  be  true  in  the  storage  rooms  (a)  of  the 
temperature ;  (6)  of  the  moisture  in  the  air  ?    What  uses  are 
made  of  the  apples  that  are  undersized,  misshapen,  and  worm- 
eaten?    What  other  uses  may  be  made  of  the  "windfalls"  ? 

12.  Describe  the  spraying  of  trees  in  an  apple  orchard, 
stating  the  material  used  and  the  manner  of  its  application. 
At  what  times  in  the  year  is  this  spraying  done?     In  some 
way  give  a  definite  idea  of  the  cost  of  doing  this,  including 
the  labor. 


150    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

13.  How  is  cider  vinegar  made  ?    How  may  this  change  be 
prevented,  and  the  cider  be  kept  sweet?    What  household 
uses  has  vinegar  ?     How  is  apple  jelly  made  ? 

14.  In  apple  raising  on  a  large  scale,  why  is  there  need 
(a)  of  good  business  ability ;    (6)  of  considerable  capital  ? 
What  degree  of  intelligence  is  required  to  make  fruit-raising 
a  success? 

WHEAT,   AND   WHEAT   GROWING 

(a)  In  the  Field1 

1.  About  what  height  has  the  wheat 
plant  as  found  in  the  field  at  the  time  of 
this  lesson  ?    About  what  will  be  its  height 
when  ready  for  the  harvest?    What  ad- 
vantages in  the  hollow  growth  of    the 
stems  as  regards  (a)  the  time  that  would 
be  required  for  growth  to  the  same  size  if 
solid;   (6)  the  strength  of  a  solid  stem 
having  the  same  amount  of  material  ? 

2.  Examine  a  growing  wheat  plant  to 
discover  if  every  stalk  is  from  a  separate 
kernel  sown.       What   is  meant   by  the 
"stooling"   of  wheat?      Note   how    far 
below   surface  the  crown  of  the  wheat 
root  grows.      What  advantage  is  there 
to  the  plant  growth  in  this? 

3.  Dig  carefully  about  a  wheat  plant 
FIG.  68.  — The  "stool-  and  ascertain  to  about  what  depth  the 

ing  "  of  grain. 

roots  grow.  , 

1  Any  field  studies  of  growing  wheat  must  of  course  be  arranged  to  suit 
local  conditions.     See  footnote  under  Temperature  Records. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES        151 

4.  Make  drawings  of  a  wheat  plant  as  a  whole,  showing  the 
roots,  stem,  leaves,  and  head.     In  what  respects  is  the  wheat 
plant  much  like  the  grasses  grown  for  hay  ? 

5.  In  case  the  wheat  seeding  was  done  by  use  of  a  drill, 
what  distance  is  found  (a)  between  rows ;  (6)  between  plants 

in  the  row  ? 

• 

(b)  In  the  Laboratory 

1.  Uproot  and  examine  some  young  wheat  plants,  grown 
in  moist  rich  soil  in  flower  jars  in  the  room.     Compare  the 
vigor  of  growth  of  several  of  the  plants  in  relation  to  the 
apparent  size  and  plumpness  of  the  kernels  from  which  they 
sprung. 

2.  Make  drawings   (a)  of  one  of  the  wheat  plants  ex- 
amined ;  (6)  of  a  wheat  head  (full  size) ;  (c)  of  cross  sections 
of  a  wheat  kernel,  both  longitudinal  and  transverse. 

3.  Side  by  side  make  sketches  of  the  heads  of  two  varieties 
of  wheat  to  show  clearly  the  points  of  difference. 

4.  Count  the  number  of  grains  rubbed  out  from  a  medium- 
sized  head  of  wheat.     Ascertain  what  per  cent  of  those  you 
obtain  are  plump  and  of  full  size.     Calculate  how  many  fold 
the  wheat  kernel  from  which  your  stalk  sprung  multiplied 
itself,  allowing  six  stalks  from  one  kernel. 

OTHER   FOODSTUFFS 

(a)  Starch 

1.  Remove  the  outside  of  a  kernel  of  wheat.  Examine 
and  describe  its  texture,  and  the  character  of  the  substance 
within  the  kernel. 


152    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

2.  Into  a  piece  of  thin  cotton  cloth  put  a  little  bran,  and 
knead  it  in  some  water  in  an  evaporating  dish  so  long  as  any 
milky  liquid  comes  out  through  the  cloth.     Continue  washing 
it  at  the  hydrant  till  the  water  runs  off  clear.      State  the 
nature  of  what  remains  in  the  cloth,  and  of  what  has  settled 
in  the  dish.     From  which  part   of  the  wheat   kernel   does 
each  come? 

3.  In  like  manner  knead  some  flour  in  a  cloth.     When  the 
white  solid  has  largely  settled,  pour  off  the  water  in  the  dish, 
and  spread  some  of  the  solid  on  a  filter  paper  to  dry  by 
evaporation.     Crumble  the  dried  solid  later  and  state  what 
it  resembles. 

Heat  some  of  this  solid  with  a  little  water  in  an  evaporating 
dish  till  the  water  boils.     Wet  a  strip  of  filter  paper  in  the 


FIG.  69.  —  Effect  of  cooking  upon  starch  granules.     Cells  of  raw  potato  are 
shown  in  a,  and  when  cooked  in  b  and  c. 

solution,  and  let  fall  drops  of  iodine  solution  at  different 
spots  on  the  paper.  Note  the  characteristic  blue  of  the  test 
for  the  presence  of  starch. 

4.  In  the  same  manner  as  in  paragraph  4  under  Eggs,  test 
some  of  the  gluten  (substance  left  in  the  cloth  from  the  flour). 
What  is  the  result? 


THE   FARM,    AND   OUR   FOOD   SUPPLIES         153 

It  is  to  be  kept  in  mind  that  the  protein  of  plant  growth  (such  as 
gluten),  and  of  the  animal  foodstuffs  (such  as  albumen  of  eggs,  casein 
of  milk,  the  fibrin  of  meat),  are  principally  tissue-building  material, 
while  starch  and  the  sugars  are  chiefly  body  fuels. 

5.  When  to  some  baking  soda  in  a  test  tube  hydrochloric 
acid  was  added  a  little  at  a  time  (paragraph  4  under  Car- 
bonates), what  gas  formed? 

Mix  thoroughly  a  very  little  baking  powder  with  a  tea- 
spoonful  of  flour.  Make  a  thick  dough  out  of  it  with  cold 
water ;  knead  it  well  with  the  fingers,  and  then  bake  it  in  a 
spoon.  Explain  the  "rising"  of  the  loaf.  Why  does  the 
loaf  retain  its  shape? 

6.  Dissolve  some  baking  powder  in  a  little  water  and  heat 
to  boiling.     Observe  the  character  of  the  liquid  when  rubbed 
between  the  fingers,  and  infer  its  meaning.     Wet  a  strip  of 
filter  paper  in  the  liquid,  and  test  with  the  iodine  solution. 

(b)   The  Sugars 

1.  Describe  all  changes  as  the  teacher  cautiously  pours 
concentrated  sulphuric  acid   into  some  thick  hot  sirup  of 
cane  sugar  in  an  evaporating  dish.     The  sulphuric   acid 
takes  hydrogen  and  oxygen  from  the  sugar  (as  H20),  leav- 
ing the  carbon  (C). 

2.  Note  the  results  carefully  when  a  few  drops  of  Fehling's 
solution  are  added  to  a  solution  of  grape  sugar  (glucose,  or 
corn  sirup)  in  a  test  tube,  and  the  liquid  is  heated  to  boiling. 

State  the  results  when  the  same  test  is  made  (a)  with  a 
solution  of  cane  sugar ;  (b)  with  a  starch  solution. 

3.  Crush  and  dissolve  some  samples  of  candies,  and  test 
for  (a)  grape  sugar;    (b)  starch.     State  your  results,  and 
their  significance. 


154    LABORATORY   LESSONS   IN   GENERAL   SCIENCE 

ORIGIN  AND  NATURE   OF   SOILS 

1.  Examine  specimens  of  quartz,  feldspar,  hornblende,  and 
mica.    Describe  each  with  respect  to  its  characteristic  appear- 
ance.    Be  sure  to  take  note  of  any  differences  in  appearance 
of  specimens  of  the  same  kind  of  mineral  (usually  due  to  ad- 
mixture of  other  earthy  material).     It  is  to  be  remembered 
that  each  of  these  substances  in  a  pure  state  is  a  somewhat 
complex  chemical  compound  of  definite  composition.     After 
becoming  familiar  with  these  type  specimens  so  that  they 
are  readily  recognized  at  sight,  identify  any  specimens  that 
may  be  assigned  you  by  numbers  only. 

2.  Examine  specimens  of  several  different  kinds  of  granite, 
and  be  able  to  point  out  in  them  particles  of  quartz  and 
feldspar,  as  well  as  any  hornblende  and  mica  (if  present). 

Examine  specimens  of  "weathered  granite."  State  which 
of  the  constituent  minerals  seems  to  possess  greatest  re- 
sistance to  decomposition. 

Whether  at  the  seashore  or  inland,  and  however  exten- 
sive its  amount,  sand  may  be  considered  as  quartz  particles 
derived  from  granitic  rock.  Clay  is  feldspar  decomposed. 
Explain  how  it  is  that  clay  and  sand,  possibly  from  the  same 
rock  sources,  are  frequently  found  as  deposits  entirely  dis- 
tinct, and  often  widely  separated.  Account  for  sandstone 
as  a  rock.  Explain  why  it  is  that  sandstone  so  often  exhibits 
a  stratified  form  (an  arrangement  in  layers). 

3.  Rub  some  dry  clay  between  the  thumb  and  finger. 
With  a  magnifying  glass  note  in  a  general  way  the  size  of  the 
clay  particles  as  seen  when  scattered  over  the  surface  of  white 
paper, 


THE   FARM,   AND   OUR   FOOD   SUPPLIES         155 

Wet  some  clay  in  an  evaporating  dish,  and  then  note  its 
feeling  and  odor  when  rubbed  between  the  fingers.  Note 
the  odor  and  feeling  of  shale  and  of  slate  when  wet. 

SOIL   CONDITIONS   FOR   PLANT   GROWTH 

1.  Recall  (a)  the  definition  of  solution;    (6)  why  sub- 
stances remain  undissolved.     Test  the  solubility  of  bits  of 
crayon  and  of  limestone  (a)  in  water;    (b)  in  hydrochloric 
acid.     Explain  any  differences  in  their  behavior. 

Whence  comes  the  water  in  the  sap  of  plants  ?  How  is  it 
possible  for  food  materials  in  the  soil  to  get  into  the  plant 
for  its  use  in  growth  and  fruitage?  What  change  in  a  sub- 
stance in  the  soil  must  often  precede  its  solution  by  the  soil 
water  ?  , 

2.  Observe  the  surface  of  any  piece  of  stone  that  has  been 
dipped  into  water.     Explain  what  is  noted.     If  the  stone  is 
now  broken  into  several  pieces,  and  all  these  are  dipped  into 
water,  what  is  true  (a)  of  the  extent  of  their  surfaces  now ; 
(b)  of  the  amount  of  water  clinging  to  these  surfaces  ? 

Break  a  blackboard  crayon  into  piece  after  piece ;  fit  the 
several  pieces  together  again,  and  then  separate  them  anew. 
What  is  manifest  as  to  the  extent  of  exposed  surfaces  of  the 
crayon  before  and  after  it  is  broken  into  pieces? 

What  would  seem  probable  of  the  amount  of  exposed  sur- 
face, and  of  the  adhering  film  of  water  (film-water),  if  division 
of  rock  materials  should  be  continued  to  the  size  (a)  of  sand ; 
(b)  of  dust  particles? 

3.  Have  three  test  tubes  about  one  third  full  and  well 
settled  by  jarring,  one  with  coarse  sand,  one  with  loam,  and 
one  with  silt.     Into  each  pour  the  same  amount  of  water, 


156     LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

enough  to  stand  above  the  surfaces.  Shake  all  well,  let 
settle  fully,  and  then  drain  off  the  water  into  separate  dishes. 
Measure  the  amount  of  such  drainage  in  each  case.  Ex- 
plain any  marked  difference. 

4.  Put  into  a  test  tube  a  half  inch  of  soil  that  apparently 
is  dry,  and  heat  it  gently.     Watch  closely  for  any  evidences  of 
moisture  in  the  tube  as  the  heating  is  continued,  and  explain. 

Examine  some  soil  that  feels  and  looks  moist.     Just  where 
in  the  soil  is  this  water,  and  how  is  it  held  in  place? 

5.  Weigh  out  several  grams  of  apparently  dry  soil  in  an 
evaporating  dish.     Heat  it  gently,  stirring  all  the  time,  and 


FIG.  70.  —  Rise  of  soil  water  by  capillarity. 

be  careful  not  to  char  or  cause  other  change  in  it  than  to 
drive  off  any  water  in  the  sample.  Weigh  anew,  and  calcu- 
late the  per  cent  of  loss  of  moisture  from  the  soil  when  dried. 

6.  Let  pieces  of  cheesecloth  be  tied  over  the  small  ends 
of  three  student-lamp  chimneys,  and  have  one  chimney 
filled  with  sand,  one  with  loam,  and  one  with  silt.  Have 
the  contents  of  the  chimneys  made  compact  by  jarring. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES        157 

Arrange  the  chimneys  so  they  are  supported  upright  with 
their  lower  cloth-covered  ends  in  a  pan  containing  about  an 
inch  of  water.1  From  time  to  time  observe  the  upward  rise 
of  the  water  into  the  chimneys  by  capillary  action,  both  its 
elevation  and  its  rapidity  of  ascent.  Account  for  any  dif- 
ferences noted. 

As  the  water  in  the  surface  layers  of  soil  in  the  field  becomes 
exhausted  by  plant  growth,  or  by  evaporation,  whence  may 
it  be  replenished  without  rainfall,  and  how? 

7.  Counterbalance  two  baking  powder  cans  that  have 
been  filled  somewhat  more  than  half  full  of  moist  soil  made 
compact  by  jarring,  the  top  of  the  soil  in  one  of  the  cans  hav- 
ing a  half-inch  layer  of  fine  dry  loam  (or  some  dust).     Ob- 
serve the  scales  from  time  to  time  through  a  day  or  two  as 
they  are  left  undisturbed.     Interpret  the  significance  of  any 
loss  of  equilibrium.     What  relation  has  this  to  the  cultiva- 
tion of  crops  during  the  growing  season? 

8.  Watch  closely  for  the  escape  of  any  bubbles  of  air  from 
a  test  tube  one  half  full  of  soil  as  an  inch  or  more  of  water  is 
poured  in  upon  the  soil,  and  account  for  the  bubbles.     What 
is  a  possible  cause  of  the  dying  of  plants  in  pots  where  any 
excess  of  water  poured  in  cannot  drain  off.     Account  for  a 
possible  crop  failure  on  low  grounds  in  wet  seasons. 

USEFULNESS   OF   PLANTS   TO   MAN 

1.  From  your  own  personal  experiences,  and  from  any 
other  sources  of  information,  prepare  lists  of  four  items  each 

1  Through  the  upper  side  of  a  box  from  which  the  front  has  been  removed 
bore  holes  of  a  size  such  as  to  allow  the  small  ends  of  the  chimneys  to  pass 
and  to  hang  suspended  in  full  view. 


158     LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

(a)  of  substances  used  in  houses  for  fuel  and  lights ;  (6)  of 
foods  eaten  uncooked;  (c)  of  food  material  prepared  for 
table  use  by  cooking  in  the  home  kitchen;  (d)  of  canned 
goods  ;  (e)  of  drinks  other  than  water ;  (/)  of  raw  materials 
for  clothing;  (g)  of  articles  of  furniture;  (h)  of  materials 
having  large  use  in  building  houses. 

In  these  lists  underscore  the  names  of  all  those  substances 
derived  directly  or  indirectly  from  plants.     (Be  ready  to 


FIG.  71.  —  Our  next  year's  clothing. 

state  in  class  just  how  this  is  in  all  cases  where  the  origin  is 
not  clearly  apparent.) 

2.  Tell  briefly  but  very  definitely  the  dependence  of  people 
upon  plants,  and  upon  the  products  manufactured  from 
them,  in  matters  (a)  of  travel ;  (6)  of  medicines ;  (c)  of  live- 
lihood ;  (d)  of  comforts  of  life ;  (e)  of  pleasant  surroundings. 


THE   FARM,   AND   OUR   FOOD   SUPPLIES        159 

3.  Name  regions  of  the  world  where  little  or  no  plant  life 
exists,  and  state  briefly  the  reason  for  each  such  case.     What 
is  true  of  animal  life  there?     What  food  supplies  are  avail- 
able there  for  men?     What  material  is  to  be  had  there 
(a)  for  dwellings ;    (6)  for  clothing  ? 

As  an  example  of  the  usefulness  of  plants  to  man,  gather  by  reading 
and  from  all  available  sources  as  full  information  as  possible  of  the 
plants  from  which  the  crude  rubber  is  obtained,  the  processes  in- 
volved in  their  cultivation,  the  harvest  and  preparation  of  this  material 
for  market,  and  its  processes  of  manufacture. 

4.  Under  appropriate  headings,  make  lists  of  the  various 
manufactured  articles  into  which  rubber  enters  for  use  in 
modern  life. 

5.  State  very  definitely  the  processes  of  rubber  manu- 
facture from  the  crude  gum  of  the  rubber  fields. 

6.  Tell  briefly  of  the  care  and  cultivation  of  the  rubber 
plantations,  and  of  the  general  character  of  the  regions  that 
are  the  chief  sources  of  rubber  supply. 


XIII.  WORK  AND  MACHINES 

MEANING    OF   THE    TERMS   WORK   AND   ENERGY 

1.  Hold  a  book  out  at  arm's  length  for  a  few  minutes. 
What  sensation  is  noticeable  in  your  arm  after  a  time? 
Regardless  of   the  fatigue  and  exhaustion  experienced  in 
this  exercise,    it   is   only   when   motion   occurs   in   bodies, 
or  in  the  particles  composing  them,  that  the  term  work 
as  used  in  Physics  is  applicable.     There  was  work   done 
in  changing  the  position  of  the  book  but  not  in  holding  it 
in  place. 

2.  Why  do  the  muscles  of  the  body  become  tired  (fatigued) 
through  exercise  when  at  labor  or  play  ?     Do  machines  such 
as  the  steam  engine  become  weary  when  at  work?    What 
does,  result  in  them  from  continued  use  ? 

3.  Name  several  changes  in  bodies  caused  by  the  action 
of  forces  upon  them.     In  which  of  these  cases  is  work  done, 
and  why  so  ? 

4.  What  is  the  basis  for  a  belief  that  there  is  any  such 
force  as  gravity?      How  does  an  intending  purchaser  of 
a  horse    assure  himself  that  the  animal  has  sight   (good 
vision)  ?     What  is  the  meaning  of  the  term  theory  as  used 
in  science,  and  in  the  affairs  of  life?    What  must  be  true 
of  any  belief,  opinion,  or  theory  if  we  are  justified  in  con- 
tinuing to  cherish  it  ?    When  must  a  theory  be  modified  or 
rejected  ? 

160 


WORK   AND    MACHINES 


161 


MEASUREMENT   OP  WORK  AND  ENERGY 

1.  With  a  spring  balance  lift  some  small  body;   note  its 
weight  in  pounds  (and  sixteenths  of  a  pound).     This  value 
represents  not  only  the  quantity  of  matter  in  the  body,  i.e., 
its  mass  (ra),  but 

as  well  the  value 
of  gravity  as  a 
force  (/)  pulling 
down  on  the 
mass,  and  the  re- 
sistance (r)  over- 
come in  lifting 
the  body.  In  the 
measurement  of 
work,  as  well  as 
of  the  energy 
used  in  doing 
that  work,  one  of 
the  units  em- 
ployed is  the  foot- 
pound. This  is  often  defined  as  the  amount  of  work  done 
(and  of  energy  used  in  doing  it)  when  a  force  of  one  pound 
causes  motion  through  one  foot  distance.  State  a  correspond- 
ing form  of  definition  for  work  when  the  term  resistance  is 
substituted  for  "force,"  and  the  phrase  is  overcome  takes 
the  place  of  "causes  motion." 

2.  Calculate  the  number  of  foot-pounds  done  when  the 
reading  of  the  balance  is  l^5y  pounds,  and  the  distance  the 
body  is  lifted  is  16  inches  (l£  feet). 


FIG.  72.  — Work  is  the  "  overcoming  of  resistance." 


162     LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

3.  Drag  the  same  body  along  the  table  through  the  same 
distance  of  16  inches,  and  as  accurately  as  possible  get  the 
balance  reading  for  the  resistance  overcome  (and  of  the  force 
used  in  overcoming  the  resistance).     In  calculating  the  work 
now  done  in  moving  the  body,  why  is  it  not  the  same  amount 
of  work  as  before? 

4.  Calculate  anew  as  in  paragraphs  2  and  3  above,  but 
this  time  take  the  balance  readings'  in  grams  for  whatever 
body  is  used,  and  let  the  distance  moved  be  in  centimeters.1 
Let  the  product  of  the  weight  (force,  or  resistance),  and  the 
distance  (or  space),  be  gram-centimeters  of  "work"  (or  of 
"energy"  used  in  doing  the  work). 

5.  Express  the  number  of  grams  above  as  kilograms,  and 
the  number  of  centimeters  as  meters.2    Then  calculate  the 
amount  of  work  done  in  kilogram-meters. 


CLASSES    OF    LEVERS 

1.  By  means  of  a  lever  clamp  support  a  meter  stick  at 
its  middle  point.  Using  loops  of  string  over  the  ends  of  the 
meter  stick,  support  any  small  weight  near  one  end,  and 
pull  down  sufficiently  on  the  other  end  with  a  spring  balance 
to  keep  the  bar  (lever)  horizontal.  Move  the  weight  (W) 
to  different  distances  from  the  point  of  support  or  fulcrum 
(F),  and  in  every  case  note  and  record  both  the  balance 
reading  (P)  and  the  distance  from  P  to  F.  For  several  of 
these  positions  of  P  and  W  get  the  product  of  P  X  Pd 
(power-distance),  and  of  W  X  Wd  (weight-distance).  These 

1  Balances  and  rulers  should  have  both  metric  and  English  scales. 

2  One  kilogram  =  1000  grams,  and  one  meter  =  100  centimeters. 


WORK   AND   MACHINES  163 

products  are  the  moments  of  P  and  of  W.  Infer  when  a 
lever  will  be  in  a  balanced  condition,  or  state  of  equilibrium. 
Make  a  drawing  that  shows  the  lever  in  some  one  of  these 
positions,  and  correctly  locate  on  it  the  positions  and  values 
of  P  and  W.  Label  the  drawing  IST  CLASS  LEVER. 

2.  Having  the  lever  supported  as  before,  put  both  P  and 
W  on  the  same  side  of  F,  and  with  W  between  P  and  F.     It 
will  now  be  necessary  to  pull  upward  with  the  spring  balance 
in  order  to  maintain  equilibrium.     Calculate  the  moments 
of  W  and  of  P  in  different  positions,  and  state  what   is 
true   of    their    relative   values    in   every   instance.     What 
is  true  in  every  case  (a)  of  the  relative  lengths  of  power 
and   weight   arms   (distances) ;    (6)   of  the  relative  values 
of  Pand  W? 

Make  a  drawing  to  represent  the  lever  in  some  one  of 
these  positions,  and  label  it  2o  CLASS  LEVER. 

3.  Arrange  the  lever  now  so  that  the  pull  of  the  balance 
(P)  is  upward,  and  between  W  and  F.     State  what  is  found 
true  under  these  conditions  (a)  of  the  moments  of  P  and  W ; 
(b)  of  the  relative  values  of  P  and  W.     Make  a  drawing  to 
represent  a  SD   CLASS  LEVER,  putting  upon  it  the  values 
found  in  some  one  of  the  cases  for  P  and  W,  and  for  Pd  and 
Wd. 

PULLEYS 

(a)  With  the  Cord  Attached  to  the  Fixed  Pulley 

It  is  desirable  to  have  a  pair  of  "triple-tandem"  pulleys  as  rep- 
resented in  the  cut,  and  a  spring  balance  graduated  both  in  grams  and 
in  ounces.  A  length  of  stout,  smooth  cord  with  loops  at  its  ends  is 
easily  provided. 


164      LABORATORY  LESSONS   IN  GENERAL   SCIENCE 

1.  Make  two  freehand  drawings  on  your  paper  similar 
to  the  cut,  showing  in  the  first  one  movable  pulley  in  use, 
and  in  the  second  two  movable  pulleys.  In  all  cases  repre- 
sent one  end  of  the  cord  attached  to  the  fixed  pulley. 


FIG.  73.  —  Diagram  of  pulleys. 

2.  Let  the  teacher  fit  up  pulleys  in  turn  representing 
these  same  conditions,  and  determine  by  use  of  the  spring 
balance  in  each  case  (a)  the  value  of  the  resistance  overcome 
(i.e.,  the  weight  of  movable  pulley  and  its  attached  body  J) ; 

1  Any  friction,  or  resistance  other  than  gravity,  is  disregarded  here. 


WORK   AND   MACHINES  165 

(6)  the  effort  put  forth  ("pull"  exerted)  to  lift  the  body.1 
Enter  on  your  drawings  the  values  found  by  the  teacher, 
marking  the  resistance  as  W  (weight),  and  the  effort  as  P 
(power). 

Be  sure  to  verify  the  correctness  of  your  drawings  by 
reference  each  time  to  the  pulley  arrangement  as  set  up  by 
the  teacher. 

3.  Let  the  teacher  take  the  readings  of  the  spring  balance 
for  the  value  of  P  (a)  when  pulling  down  over  the  last  of  the 
fixed  pulleys;    (6)  when  lifting  up,  and  not  using  this  last 
fixed  pulley.     Infer  (a)  the  only  purpose  of  this  fixed  pulley ; 
(6)  whether  the  section  of  cord  for  pulling  downward  shall 
be  counted  in  any  case  as  a  supporting  cord  for  W. 

4.  From  inspection  of  your  diagrams,  and  of  the  values 
of  P  and  W  shown  thereon,  state  what  appears  true  (a)  of  the 
number  of  cords  supporting  W  relative  to  the  number  of 
movable  pulleys ;    (6)  of  the  fractional  part  of  W  supported 
by  each  cord;    (c)  of  the  ratio  (approximately)  of  W  to  P 
relative  to  the  number  of  such  cords. 

5.  Measure  the  distances  through  which  P  moves  in  all 
of  the  cases  above  when  W  is  raised  through  a  distance  of 
one  foot  every  time.     State  for  each  case  how  many  times 
greater  the  power-distance  (Pd)  is  than  the  weight-distance 
( Wd) .     How  does  this  compare  with  the  number  of  support- 
ing cords  in  each  case? 

6.  Since  P  traverses  the  distance  Pd  in  the  same  time 
that  W  moves  through  Wd,  what  must  be  true  of  the  rela- 

1  For  this  value  of  P  take  the  average  of  the  readings  of  the  spring  balance 
as  W  is  drawn  slowly  upward,  and  then  again  as  W  is  allowed  to  descend 
slowly.  In  this  way  the  value  of  the  resistance  due  to  friction  of  the 
pulleys  is  quite  largely  eliminated. 


166     LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

tive  values  of  the  velocities  of    P  (Pv)  and  of  W  (Wv)  in 
all  cases  ? 

What  are  the  relative  values  (a)  of  P  times  Pd,  and  W 
times  Wd ;   (b)  of  P  times  Pv,  and  W  times  Wv  ? 

(b)  With  the  Cord  Attached  to  the  Movable  Pulley 

7.  Make  two  other  drawings  to  show  the  arrangement 
of  pulleys,  and  the  values  for  P  and  W  as  directed  in  para- 
graphs 1  and  2  above,  but  this  time  with  the  end  of  the  cord 
attached  to  the  movable  pulley. 

8.  Determine  the  values,   and  state  the  relationships 
now  apparent  as  required  in  paragraph  4  above. 

9.  Answer  the  same  requirements  as  in  paragraphs  5 
and  6  above,  with  the  conditions  as  they  are  now. 

10.  Disregarding  any  waste  of  energy  due  to  friction, 
what  seems  true  of  the  relative  value  of  the  work  done 
(W  times  Wd),  and  of  the  energy  used  in  doing  this  work 
(P  times  Pd)  ? 

11.  State  some  of  the  advantages  from  the  use  of  pulleys 
as  machines  (a)  over  the  direct  application  of  any  force  to  a 
body  that  is  to  be  moved ;   (b)  over  the  use  of  levers  of  any 
kind. 


XIV.  MAGNETISM  AND  ELECTRICITY 

ELECTROMAGNETS 

1.  Bring  first  one  end  of  a  bar  magnet  and  then  the  other 
to  the  north  pole  of  a  compass  needle.     Try  the  south  pole 
of  the  needle  in  like  manner.     State  what  appears  true  of  the 
effect  upon  each  other  (a)  of  like  poles ;    (b)  of  unlike  poles. 

2.  Compare  the  number  of  small  nails  that  one7  pole  of  a 
bar  magnet  will  support  with  the  number  that  can  be  picked 
up  (a)  when  the  like  poles  of  two  bar  magnets  are  used 
together ;    (6)  when  their  unlike  poles  are  together. 

3.  Put  a  bar  magnet  across  one  pan  of  a  balance,  and 
counterpoise  it.     Bring  close  above  its  north  pole  the  south 
pole  of  another  bar  magnet,  and  state  the  results.     What  is 
all  the  time  true  of  the  weight  of  the  magnet  ?    Account  for 
what  occurred. 

Bring  the  balance  into  equilibrium.  Repeat  the  test, 
bringing  like  poles  together.  Explain  the  result. 

4.  Observe  closely  as  the  teacher  connects  a  "dry  cell" 
to  the  ends  of  the  coil  of  an  electromagnet,  and  tests  the 
effect  of  the  magnet  upon  nails. 

Determine  by  trial  which  is  the  north  pole  of  the  electro- 
magnet while  connected  with  the  cell.  Mark  this  pole  N. 
Then  connect  the  coil  with  the  cell  so  that  the  current  is  sent 
through  the  coil  in  the  opposite  direction,  and  test  the 
polarity  anew.  State  all  the  results. 

5.  Note  about  how  many  nails  the  electromagnet  supports 
when  the  current  is  passing  through  the  coil.     As  carefully 

167 


168      LABORATORY  LESSONS   IN  GENERAL  SCIENCE 


as  possible  let  the  connection  with  the  cell  be  broken,  and 
note  the  effect.  Repeat  several  times  to  be  sure  of  the  con- 
dition of  the  coil  as  the  circuit  is  (a)  opened;  (b)  closed. 
State  the  results. 


^- 


6.  Observe  closely  the  results  when  the  teacher  connects 
a  dry  cell  to  an  electric  bell  in  working  order.  (Use  two  cells 

if  necessary.) 

Describe  the  course 
of  the  current  through 
the  bell,  tracing  it  very 
carefully  with  such  as- 
sistance as  may  be 
needed. 

Notice  the  effect  on 
the  hammer  of  the  bell 
as  the  circuit  is  closed 
and  opened.  Explain 
(a)  why  the  hammer 
is  drawn  towards  the 


FIG.  74.  —  The 


electric    bell,    and    how    it 
operates. 


coil;  (b)  why  it  flies 
back  from  the  coil. 
Explain  how  the  "make  and  break"  of  the  circuit  .is  ac- 
complished automatically  with  the  battery  connections 
continuously  maintained. 

State  several  possible  causes  why  electric  doorbells  may 
fail  to  operate.  What  may  be  done  to  locate  the  particular 
cause  of  trouble  in  order  to  remedy  it  ? 

7.  Connect  a  telegraph  key  into  the  circuit  between  the 
battery  and  the  bell;  make  use  of  it  to  close  and  to  open 
circuit,  thus  ringing  the  bell  at  pleasure.  Describe  the 


MAGNETISM   AND   ELECTRICITY 


169 


connection  through  the  key,   and  explain  the  use  of  the 
key. 

8.  Substitute  for  the  bell  a  sounder  from  a  set  of  telegraph 
instruments,  and  by  use  of  the  key  cause  the  sounder  to 
operate..  Describe  the  course  of  the  current  through  the 
sounder,  and  its  manner  of  operation  as  the  circuit  is  closed 
and  opened.  State  (a)  when  the  sounder  might  operate  so 
feebly  as  to  make  it  impossible  to  read  its  clicks  distinctly ; 
(b)  two  ways  in  which  to  remedy  this. 


ELECTRICITY,    AND    CHEMICAL    CHANGES 

1.  Fill  the  tumbler  of 
a  simple  voltaic  cell  as 
shown  in  the  cut  two 
thirds  full  of  water. 
Have  both  the  zinc  and 
the  copper  strips  of  metal 
scoured  bright  with  sand- 
paper. To  the  water 
add  sulphuric  acid  a  few 
drops  at  a  time  till,  as 
the  water  is  stirred  with 
the  zinc  strip,  bubbles 
form  on  the  metal  sur- 
face somewhat  freely. 
These  are  not  air  bubbles, 
but  the  gas  is  hydrogen 
formed  as  result  of 

chemical  change  between  the  acid   (H2SO4)   and  the  zinc 
(Zn).     It   has  been  found  by  tests  made  very  many  times 


FIG.  75. —  A  simple  voltaic  cell. 


170     LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

that  there  is  formed  at  the  same  time  one  other  substance, 
zinc  sulphate  (ZnSO4),  which,  so  long  as  the  water  can  hold 
it  in  solution,  dissolves  as  fast  as  it  forms.  When  the 
water  becomes  saturated  (filled)  with  it,  the  ZnSO4  will  then 
be  deposited  as  a  solid. 

2.  Chemists  have  a  shorthand  way  of  stating  chemical 
changes  known  to  have  taken  place,  and  in  this  case  the  state- 
ment would  be  Zn  +  H2SO4  ->  H2  +  ZnSO4.     The    arrow 
points  toward  the  products  of  chemical  change,  and  in  these 
products  there  must  always  be  the  same  weight  of  material 
(and  same  numbers  of  atoms  of  the  substances)  as  found 
in  the  substances  entering  into  the  change. 

3.  Test  the  action  of  the  dilute  acid,  (a)  using  the  copper 
(Cu)  strip  in  place  of  the  zinc ;   (6)  putting  both  strips  down 
into  the  liquid  at  the  same  time  but  not  allowing  the  metals 
to  touch  each  other  either  within  the  liquid  or  outside. 

4.  Fasten  in  place  in  the  cap  of  the  simple  cell  a  strip 
each  of  copper  and  of  zinc.     Connect  the  binding  posts  in 
contact  with  these  strips  by  a  copper  wire  a  couple  of  feet 
in  length.     Now  put  the  cap  in  place  on  the  tumbler  with 
the  metal  strips  in  the  liquid  close  together  but  not  touching 
each  other.     Observe  the  strips  in  the  liquid  long  enough  to 
state  what  change  from  the  former  conditions  is  now  noted. 

5.  Bring  the  wire  connecting  the  binding  posts  down 
lengthwise  over  a  compass  needle  which  is  at  rest  in  a  north 
and  south  direction,  and  note  the  effect.      Repeat  several 
times  to  be  sure  whether  any  disturbance  of  the  needle  re- 
sults from  the  presence  near  it  of  a  current-bearing  ("live") 
wire.     Note  the  effect  on  the  compass  needle  of  bringing 
near  it  and  of  taking  away  a  permanent  magnet.     Try  a 


MAGNETISM   AND   ELECTRICITY  171 

piece  of  iron ;  then  try  other  substances.  Since  the  wire 
is  copper  (not  iron),  what  seems  to  be  a  characteristic  of  a 
wire  in  which  a  current  of  electricity  is  passing? 

6.  Repeat  the  tests  upon  the  compass  needle,  but  this 
time  use  a  dry  cell  with  its  binding  posts  connected  by  cop- 
per wire.     State  the  results,  and  their  significance. 

7.  Cut  the  wire,  joining  the  binding  posts  of  the  dry  cell, 
in  the  middle,  and  test  the  effect  on  the  compass  needle  of 
the  wires  of  the  "  broken  circuit."    Bring  the  ends  of  the  wires 
together  on  either  side  of  a  thickness  of  paper,  and  determine 
if  the  current  completes  a  circuit  through  the  paper. 

8.  Connect  the  ends  of  the  wires  fastened  to  the  binding 
posts  of  the  dry  cell  to  the  binding  posts  in  the  cap  of  an- 
other simple  cell  into  which  two  copper  strips  have  been 
fastened.    These  copper  strips  are  now  the  terminals  of  a 
broken  circuit.     Put  these  strips  down  into  a  second  tumbler 
containing  some  water,  being  careful  to  keep  them  near 
each  other  but  not  touching.     By  bringing  one  of  the  con- 
necting wires  down  over  the  compass  needle  at  rest,  de- 
termine if  the  circuit  has  been  closed  through  the  water.    To 
the  water  add  a  little  sulphuric  acid  and,  after  stirring  the 
liquids  well,  test  the  effect  of  the  wire  on  the  compass  anew. 
The  acid  serves  as  a  carrier  of  electricity  across  from  one 
terminal  to  the  other,  and  is  said  to  be  an  electrolyte.     Many 
substances  in  solution  would  behave  in  a  similar  manner,  but 
not  all  solutions  are  electrolytes*. 

9.  Repeat  paragraph  8,  but  this  time  use  with  the  water 
a  little  copper  sulphate  (CuSO4)  for  the  electrolyte.     After 
some  time  with  the  circuit  closed  examine  the  copper  plates 
for  changes  in  appearance. 


XV.   PHENOMENA  OF  LIGHT 
SHADOWS   AND  ECLIPSES 

1.  Let  the  room  be  darkened,  and  a  lighted  candle  so 
arranged  that  a  well-defined  shadow  of  some  opaque  body 
is  made  to  fall  on  a  white  wall-surface  or  other  screen.     By 
moving  a  sheet  of  paper  back  and  forth  between  the  screen 
and  the  body  determine  how  many  dimensions  a  shadow 
actually  has,  i.e.,  whether  a  shadow  is  a  darkened  region 
(space)  or  a  darkened  surface.     That  which  is  seen  on  a 
screen  or  wall  bears  what  relation  to  the  real  shadow?     If 
there  had  been  no  screen  across  the  path  of  the  shadow,  what 
would  have  been  true  of  its  extent  outward  ? 

2.  Note  if  there  is  any  sharp  line  of  division  between  the 
umbra  (dark  part  of  the  shadow)  and  the  penumbra  (the 
lighter  outer  portion).     Determine  if  the  umbra  extends 
lengthwise  throughout  the  shadow  region. 

Support  a  sheet  of  paper  so  that  a  pinhole  through  the 
paper  may  be  jnoved  in  turn  through  the  umbra,  the  pe- 
numbra, and  then  outside  the  darkened  area.  By  looking 
through  the  pinhole  towards  the  candle  flame  determine 
(a)  the  reason  for  the  existence  of  any  shadow;  (b)  the 
cause  of  the  distinction  between  umbra  and  penumbra,  and 
why  they  merge  without  a  sharp  line  of  division. 

3.  Make  such  arrangements  that  enough  direct  (or  re- 
flected) sunlight  may  come  into  a  darkened  room  to  strongly 
illuminate  a  small  ball  that  is  to  represent  the  earth. 

172 


PHENOMENA    OF   LIGHT  173 

By  use  of  a  sheet  of  paper  moved  back  and  forth  in  the 
shadow  cast  by  the  ball,  determine  (a)  the  form  of  the  shadow 
region ;  (b)  its  extent  outward  (length) ;  (c)  the  form  of 
cross  section  at  right  angles  to  the  direction  of  the  shadow ; 
(d)  where  the  base  of  the  shadow  is.  Leave  the  screen 
supported  in  some  way  in  the  path  of  the  shadow  so  that 
cross  sections  of  both  umbra  and  penumbra  show  upon  it. 

4.  Making  use  of  a  small  marble  to  represent  the  moon, 
cause  it  to  move  round  and  round  the  ball  in  a  path  (orbit) 
that  at  times  passes  (a)  through  the  umbra  of  the  shadow; 
(b)  only  in  part  into  the  umbra ;   (c)  through  the  penumbra 
only,  or  wholly  outside  the  shadow  in  the  region  of  illumi- 
nation. 

State  the  conditions  that  apparently  must  exist  (a)  for 
total  eclipses  of  the  moon ;  (b)  for  partial  eclipses ;  (c)  for 
failures  to  have  a  lunar  eclipse  every  month.  From  which 
side  of  the  earth  with  reference  to  the  sun  are  eclipses  of 
the  moon  to  be  seen?  During  which  part  of  the  twenty- 
four  hours  will  this  be  for  the  observer? 

5.  As   the   marble    (representing   the   moon)   is   moved 
around  the  ball,  try  to  visualize  (a)  the  revolution  of  the 
real  moon  about  the  earth,  and  in  a  path  such  that  it  comes 
between  the  sun  and  an  observer ;   (b)  the  onward  sweep  of 
the  moon's  shadow  across  the  earth's  surface  as  it  approaches 
the  observer,  envelops  him  in  an  "eclipse  of  the  sun"  and 
passes  on  to  the  eastward  beyond  him.     In  so-called  eclipses 
of   the  sun,  what   really   suffers   eclipse,   i.e.,   passes  into 
shadow?    What  must  be  true  of  the  duration  of  a  solar 
eclipse  at  any  station? 

In  what  part  of  the  moon's  shadow  must  an  observer  be 


174      LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

that  an  eclipse  of  the  sun  is  total  rather  than  partial  ?  What 
change  in  the  moon's  distance  from  the  earth  when  it  is 
directly  in  line  between  an  observer  and  the  sun  will  result 
in  its  not  wholly  covering  the  sun's  disk?  The  moon  will 
then  appear  as  a  dark  body,  and  the  sun  as  a  ring  of  light 
all  round  the  moon's  edge  —  an  annular  (ringlike)  eclipse. 
Make  a  diagram  showing  these  conditions. 


FIG.  76.  —  Diagram  showing  conditions  for  solar  and  lunar  eclipses. 

6.  Total  solar  eclipses  are  very  rare  occurrences  for  any 
one  locality  on  earth.     What  evident  connection  is  there 
between  this  infrequency  and  (a)  the  length  of  the  moon's 
shadow ;   (6)  the  size  (cross  section)  of  the  umbra  near  its 
apex? 

7.  From  the  diagram  above  find  the  apparent  reason 
why  the  moon  gets  into  the  earth's  shadow  (lunar  eclipse) 
more  often  than  an  observer  on  the  earth  is  in  the  moon's 
shadow  (solar  eclipse). 

8.  The  period  of  the  earth's  revolution  about  the  sun  is 
somewhat  more  than  365  days,  while  that  of  the  moon  about 
the  earth  is  28  days.     How  many  full  moons  per  year  are 
possible?     How  many   total   eclipses   of  the   moon?     As- 
certain from  the  almanac  (or  otherwise)  how  many  are  to 
occur  during  this  calendar  year?     Why  are  there  no  more? 

9.  Make  a  drawing  that  shows  the  sun,  the  earth  and  its 
moon,  and  Jupiter  with  at  least  one  of  its  moons,  so  arranged 
as  to  represent :  — 


PHENOMENA    OF   LIGHT 


175 


(a)  Shadows  cast  by  both  Earth  and  Jupiter,  and  by  the  satellites 
of  both  planets,  with  positions  such  that  eclipses  of  the  moons  are 
about  to  occur  in  both  cases. 

(6)  The  earth's  moon  in  such  a  position  that  an  eclipse  of  the  sun  is 
about  to  occur. 


FIG.  77.  —  The  velocity  of  light  was  calculated  from  observations  made  by 
astronomers  of  the  time-intervals  between  eclipses  of  the  inner  satellite 
of  Jupiter. 

10.  Astronomers  tell  us  that  the  innermost  of  the  moons 
of  Jupiter  is  eclipsed  at  every  revolution.  Tell  several 
astronomical  conditions  implied  in  this  statement. 


IMAGES  BY  REFLECTION 

1.  Hold  a  small  looking-glass  in  the  sunlight  at  a  window 
and  state  the  effect  (a)  on  the  direction  of  light  as  it  comes 
from  the  sun ;   (6)  on  the  degree  of  illumination  where  this 
reflected  light  now  falls.     Distinguish  between  incident  rays 
and  reflected  rays. 

2.  Hold  a  mirror  so  that  the  reflected  light  of  a  candle 
flame  enters  the  eye.     What  is  seen  in  the  mirror?     Call  it 
an  image  of  the  flame.     Along  which  rays  of  light  is  this  to 
be  seen  ?    Why  is  it  seen  in  this  particular  direction  and  not 
in  some  other? 


176      LABORATORY  LESSONS   IN   GENERAL  SCIENCE 

3.  With  a  lighted  candle  close  in  front  of  a  looking-glass, 
how  many  flames  are  to  be  seen  ?    Where  does  the  one  that 
is  not  a  real  flame  seem  to  be? 

4.  Set  the  lighted  candle  so  that  it  shall  be  hidden  behind 
a  book,  but  let  its  image  be  in  sight.     State  the  course  of 
the  light  from  the  candle  flame  to  the  eye. 

Attempt  to  take  hold  of  what  seems  to  be  a  candle  image 
behind  the  glass.  Move  a  screen  (a  sheet  of  paper)  back 
and  forth  where  it  seems  to  be.  What  is  true  of  the  reality 
of  this  candle  image?  Call  it  a  virtual  image.  What  kind 
of  surfaces  form  these  images?  What  is  the  effect  of  such 
surfaces  on  the  light  that  falls  upon  them? 

5.  Hold  a  lead  pencil  with  the  point  towards  the  glass. 
In  what  direction  does  the  pencil  image  point  ?    As  you  look 
in  the  glass,  touch  your  right  hand  to  your  right  ear.     Which 
hand  and  which  ear  of  the  image  seems  to  be  employed? 
(The  image  is  reversed,  i.e.,  turned  right  and  left.)     What 
is  the  relative  size  of  the  object  and  image  ? 

6.  In  front  of  a  looking-glass  lay  a  foot  rule  perpendicular 
to  the  mirror.     How  far  back  of  the  mirror  does  the  image 
of  the  3-inch  mark  appear  to  be?    How  far  back,  appar- 
ently, is  the  5-inch  mark? 

7.  On  a  sheet  of  paper  set  a  mirror  upright  (on  edge), 
and  near  it  place  a  ruler  somewhat  oblique  to  the  mirror 
surface.     Draw  lines  along  both  the  mirror  front  and  the 
marked  edge  of  the  ruler.     Locate  on  the  latter  the  2-inch 
and  4-inch  marks. 

Remove  the  paper,  and  draw  lines  from  the  2-inch  and  4- 
inch  marks  perpendicularly  through  the  mirror  line  for  some 
distance.  Replace  the  mirror  and  rule,  and  note  where  such 


PHENOMENA    OF   LIGHT 


111 


perpendicular  lines  (normals)  appear  to  pass  with  reference 
to  the  images  of  the  2-inch  and  4-inch  marks. 

8.  Draw  a  line  on  a  sheet  of  paper  to  represent  a  mirror 
surface,  and  in  front  of  it  a  3-inch  arrow  oblique  to  this  line. 
Having  in  mind  what  is  suggested  in  paragraph  7,  locate 
the  image  of  this  arrow  on  the  other  side  of  the  mirror  line 
by  use  of  ruler  and  protractor. 

COLOR   PHENOMENA 

Note  carefully  the  procedure  as  the  teacher  follows  out  the  direc- 
tions given  below.  Be  ready  to  state  the  results  obtained,  and  the 
significance  of  them  as  called  for  in  turn. 

1.  So  adjust  a  triangular  glass  prism  in  a  beam  of  sun- 
light as  to  get  a  solar  spectrum  on  a  white  wall  of  the  room 
(or  other  screen) . 
Then  darken  the 
room.  By  use  of 
a  strip  of  card  put 
over  the  prism 
faces,  determine 
(a)  through  which 
face  the  incident 
light  enters; 
(6)  through  which 
the  light  emerges. 
Call  the  edge  formed 
by  the  intersection 
of  these  faces  the 
refracting  angle  of 

the  prism,  and  the  side  opposite  it  the  "base"  of  the  prism. 
Note  (a)  whether  the  change  in  direction  of  the  incident 

N 


FIG.  78.  —  Dispersion  of  light,  and  the  solar 
spectrum. 


178      LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

rays  is  toward  the  base,  or  away  from  it ;  (6)  which  of  the 
colors  of  the  spectrum  is  bent  farthest  around,  and  which 
least.  Name  these  colors  of  the  solar  spectrum  in  order, 
beginning  with  the  red. 

A  spectrum,  whatever  the  source  of  light,  is  defined  as 
an  arrangement  of  colors  in  the  order  of  their  refrangibility,  i.e., 
according  to  the  degree  they  are  bent  from  a  straight  line 
by  refraction.  Refraction  of  light  by  definition  is  a  bending 
of  the  rays,  i.e.,  a  change  in  the  direction  of  light,  by  reason 
of  changes  in  the  density  of  medium.  (As  from  air  into 
glass,  and  then  from  glass  into  air.) 

2.  Using  a  sheet  of  writing  paper  that  has  been  dipped 
into  hot  melted  paraffine  to  make  it  translucent,  trace  the 
emergent  rays  outward  from  the  prism  and  note  (a)  what 
their  relative  direction  is  after  refraction ;   (b)  why  it  is  that 
refraction  commonly  occurs  without  noticeable  dispersion. 

3.  Let  some  one  on  the  far  side  of  the  room  look  through 
a  long  narrow  opening  in  a  cardboard  held  for  him  in  the 
different  color  parts  of  the  spectrum  in  turn,  and  tell  in  each 
case  what  the  color  sensation  is. 

4.  Let  the  spectrum  fall  upon  a  plane  mirror,  and  note 
(a)  what  is  done  to  the  light  waves  giving  the  spectrum  col- 
ors ;    (6)  whether  there  has  been  any  change  in  the  relative 
positions  of  these  colors.     Explain   how  it   is   that  all  of 
these  different  colors  (light  waves)  come  to  every  one  of 
you,  although  you  are  seated  in  different  parts  of  the  room. 

5.  Hold  a  narrow  strip  of  blue  cardboard  (as  pure  blue 
as  obtainable)  in  different  parts  of  the  spectrum,  and  note 
its  changes  in  appearance.     It  is  explained  that  any  pigment 
(the  material  upon  which  the  color  of  a  body  depends)  re- 


PHENOMENA    OF   LIGHT  179 

fleets  some  waves  (colors)  more  largely  than  others,  and  ab- 
sorbs the  different  color  elements  incident  upon  it  in  vary- 
ing proportions. 

Repeat  the  tests,  using  in  turn  cards  of  different  colors. 
(Get  as  nearly  pure  colors  as  can  be  had.)  Explain  the 
results  as  phenomena  of  selective  absorption. 

Explain  (a)  the  green  of  the  grass ;  (b)  the  yellow  of  gold ; 
(c)  the  white  of  any  painted  house. 

6.  With  a  piece  of  blue  (cobalt)  glass  so  held  that  light 
from  the  window  comes  through  it  to  you,  explain  selective 
transmission.  In  like  manner  use  a  piece  of  red  glass,  and 
explain. 

Now  put  the  two  pieces  of  red  and  blue  glass  together, 
and  between  you  and  the  light  from  the  window.  Account 
for  the  results. 

Observe  the  spectrum  on  the  screen  as  first  the  blue  glass 
is  put  near  the  prism  in  the  path  of  the  emergent  rays,  then 
the  red  glass,  and  then  both  glasses.  What  is  the  explana- 
tion of  these  results  ? 


XVI.  THE  EARTH  AS  A  PLANET 

DAY  AND  NIGHT,  AND  THE  EARTH'S  ROTATION 

1.  When  the  sun  rose  this  morning,  in  what  direction  was 
it  from  due  east  ?     (Be  ready  when  called  upon  to  point  out 
where  the  sun  rose.)     About  what  time  was  it?    What  is 
the  time  now  ? 

Where  is  the  sun  now?  What  has  it  done  (apparently) 
since  you  first  saw  it  this  morning?  In  what  direction  will 
it  be  at  sunset  to-night  ?  Why  do  you  think  so  ?  What  do 
you  ordinarily  mean  by  (a)  sunset ;  (6)  sunrise  ? 

Where  will  the  sun  be  to-morrow  morning?  Why  is  it 
reasonable  to  expect  this? 

2.  What  is  the  common  distinction  between  daytime  and 
nighttime?     Why  is  the  nighttime  better  for   sleep,   and 
the  daytime  better  for  our  varied  activities?      Name  some 
occupations  in  which  men  labor  all  night,  and  sleep  by  day. 

How  many  hours  in  a  day  (both  daytime  and  night- 
time) ?  From  what  time  to  what  time  may  the  length  of  a 
day  be  best  measured?  What  fractional  part  of  such  a 
period  is  an  hour?  How  are  the  lengths  of  minutes  and 
seconds  determined?  Calculate  how  many  minutes  there 
are  in  a  day  (24  hours). 

3.  Hold  a  cardboard  edgewise  against  the  right  side  of 
the  face,  thus  shutting  out  of  sight  objects  far  around  on 
that  side.     Turn  slowly  towards  the  right  without  change 
of  standing  place,  and  state  (a)  what  is  found  true  of  the 

180 


THE   EARTH   AS   A    PLANET  181 

angular  distance  of  any  visible  object  from  the  direction 
(plane)  of  the  cardboard  as  you  turn  more  and  more;  (6) 
what  is  found  true  of  the  relative  distances  apart  at  differ- 
ent times  of  any  two  objects  in  sight ;  (c)  how  far  around  one 
must  turn  that  an  object  shall  apparently  have  moved  90 
degrees  from  the  plane  of  the  cardboard. 

4.  Repeat  the  above  but  with  cardboards  extending  out- 
wards  from   both   sides  of   the   face.     State   (a)  when  an 
object  may  be  said  to  "set" ;  (b)  how  far  around  one  must 
turn  that  an  object  which  has  once  " set"  may  "rise"  again ; 
(c)  the  significance  of  saying  that  an  object  thus  coming  into 
view,  and  then  disappearing  behind  the  cardboard  horizon, 
has  an  "apparent  motion"  ;  (d)  where  the  real  motion  exists. 

5.  What  do  you  mean  by  the  east  horizon  of  any  ob- 
server?    By  the  west  horizon?     What  prevents  our  seeing 
the    sun   when    it 

is  below  the  west 
horizon  ? 

Instead  of  think- 
ing of  the  sun  as 
moving  down  be- 
low the  west  hori- 

.    ,     »   ,,  FIG.  79.  —  The  horizon  at  sea. 

zon    at    nightfall, 

think  of  the  sun  as  standing  still.     Account  for  the  so-called 

"setting"  of  the  sun.     What  does  "sunrise"  really  mean? 

6.  Use  a  sphere  with  a  heavy  wire  axis  to  represent  the 
earth,  and  by  means  of  a  thumb-tack  fix  a  spot  on  the  sphere 
that  represents  your  position  as  an  observer  in  the  northern 
hemisphere.     Let  this  same  tack  hold  in  place  for  an  horizon 
plane  a  circular  cardboard  sufficiently  large  to  have  the 


182     LABORATORY  LESSONS  'IN  GENERAL  SCIENCE 

wire  axis  reach  up  through  and  above  it.  Turn  the  sphere 
together  with  this  cardboard  horizon  on  the  wire  as  an  axis, 
i.e.,  rotate  the  sphere.  Note  that  the  east  horizon  (front 
edge)  falls  lower  and  lower  below  objects  which  were  at  first 
out  of  sight  of  an  observer  as  located  by  the  tack,  thus 
causing  them  to  "rise."  Note,  too,  that  the  opposite  (west) 
horizon  of  the  cardboard  passes  objects  and  shuts  them  from 
view,  causing  them  to  "set"  for  the  same  observer. 

Explain  (a)  how  this  exhibits  succession  of  daytime  and 
nighttime  on  the  earth;  (b)  how  it  is  that  when  we  have 
nighttime,  and  can  see  the  stars^  there  are  people  elsewhere 
in  the  world  who  are  having  daytime. 

7.  With  the  sphere  and  a  lighted  candle,  but  without  the 
cardboard,  note  how  by  turning  the  sphere  on  its  axis  the 
marked  place  of  the  observer's  position  comes  around  on 
the  side  where  the  light  is,  then  passes  through  the  region 
of  illumination  (daytime),  and  then  on  for  a  period  (night- 
time) when  the  light  cannot  be  seen. 

Repeating  such  rotation,  state  when  for  the  observer  on 
the  earth  there  occurs  (a)  sunrise ;  (b)  noonday ;  (c)  sunset. 
State  (a)  how  often  these  occur;  (b)  when  a  day's  period 
is  completed.  Why  is  the  sun  not  seen  at  all  times  ? 

8.  Define  for  a  rotating  body  (a)  axis;    (6)    poles;    (c) 
equator ;  (d)  parallels  of  latitude. 

9.  Repeat  paragraph  7,  holding  the  sphere  so  that  the 
illumination  reaches  from  pole  to  pole.     State  where  a  line 
drawn  from  the  source  of  light  to  the  center  of  the  sphere 
cuts  the  surface  of  the  sphere.     Letting  the  light  represent 
the  sun  and  the  sphere  the  earth,  state  where  on  the  earth 


THE   EARTH   AS   A    PLANET  183 

the  sun  would  thus  be  directly  overhead  as  the  earth  turns 
on  its  axis. 

State  the  relative  lengths  of  the  path  of  the  observer 
through  the  illuminated  and  the  unilluminated  regions,  and 
of  the  day  and  night  periods  for  the  observer. 

ROTATION  COMBINED  WITH  REVOLUTION,   AND 
CHANGES   IN   SEASONS 

Upon  a  crayon  box  on  the  table  support  horizontally  an  ellipse  that 
has  been  cut  from  heavy  cardboard.  Its  major  axis  (long  diameter) 
should  be  at  least  two  feet,  and  its  sides  so  slightly  flattened  that  it  is 
very  nearly  a  circle.  Let  its  circumference  represent  the  earth's  path 
around  the  sun  (the  earth's  orbit).  Into  a  hole  a  little  at  one  side  of 
the  center  (and  toward  one  "end")  crowd  a  marble  nearly  halfway 
through  to  represent  the  position  of  the  sun  in  the  earth's  orbit. 

1.  What  is  meant  (a)  by  an  ellipse;  (6)  by  the  revolution 
of  a  body  as  distinguished  from  rotation  ?  Around  this 
elliptical  circumference  carry  several  times  the  sphere  that 
represents  the  earth,  always  observing,  however,  these  two 
directions :  — 

1.  Have  the   sphere  tipped  northward  so  that   its   axis 
makes  an  angle  of  approximately  23J°  with  a  perpendicular 
to  the  cardboard.     (This  tips  the  axis  about  one  fourth  way 
over  from  a  vertical  position.) 

II.  Keep  the  direction  of  the  axis,  no  matter  where  the 
sphere  is  placed,  at  all  times  parallel  to  this  first  direction, 
This  makes  it  at  all  times  point  towards  the  North  Star  in 
the  heavens. 

2.  Adjust  the  ellipse  so  that  when  4the  sphere  is  placed  at 
the  end  of  the  major  axis  nearer  the  marble,  the  north  pole 
of  the  sphere  (earth)  is  tipped  away  from  the  marble  (sun). 
Then  state :  — 


184     LABORATORY  LESSONS   IN  GENERAL  SCIENCE 


(a)  Where  vertical  rays  from  the  sun  (direction  from  center 
to  center  of  spheres)  fall  on  the  earth  relative  to  its  equator. 

(6)  What  circles  on 
the  earth  are  marked 
I  out  by  these  vertical 
rays,  and  by  those 
rays  reaching  farthest 
north  and  farthest 
south,  as  the  earth 

FIG.  80.  — December  21st.  js  made  to  rotate  ? 

3.  Move  the  sphere  representing  the  earth  a  quarter  way 
round  the  cardboard  to  the  right  (as  one  faces  the  center), 
observing    all    the     re- 
quirements of  I  and  II 

in  paragraph  1  above. 
State  what  is  now  noted 
as  required  in  (a)  and 
(6)  of  paragraph  2. 

4.  Move    the    sphere 
to  the  other  end  of  the 

.    „       .  FIG.  81.  — March  21st,  and  September  22d. 

major  axis,  and  farthest 

from  the  marble.     State  as  in  paragraph  2,  (a)  and  (6). 

5.  Move  the  sphere  on  to  three  quarters  of  the  way 
around  the  cardboard,  and  state  as  above. 

6.  When  a  complete  revolution  of  the  earth  about  the  sun 
is  accomplished,  what  period  of  time  has  elapsed?    In  the 
northern  hemisphere,  what  season  of  the  year  is  represented 
by  each  of  the  four  positions  of  the  sphere? 

7.  State  in  detail  why  these  changes  in  the  position  of 
the  earth  in  its  orbit  cause  changes  of  seasons  for  us, 


THE   EARTH   AS   A    PLANET 


185 


8.  Let  a  sheet  of  paper,  whose  edge  is  cut  out  to  fit  down 
over  the  sphere,  be  so  adjusted  perpendicular  to  the  card- 
board that  it  marks  the 
separation  of  the  regions 
of  darkness  and  of  illu- 
mination when  the  sphere 
is  placed  as  in  paragraph 
2  above.  Rotate  the 
sphere,  and  note  the 
relative  lengths  of  the  FIG.  82.  — June  21  st. 

paths  through  the  daylight  and   nighttime  regions  for  an 
observer  in  the  northern  hemisphere. 

Do  the  same  for  the  positions  as  given  in  paragraphs  3,  4, 
5  above,  and  state  what  is  apparently  true  of  the  relative 
lengths  of  day  and  night  for  each  of  the  different  seasons. 


THE   MOON,   AND   ITS   PHENOMENA 

(a)  Observations1 

Let  every  one  look  for  the  moon  to-night  (or  on  the  first  clear  night), 
as  early  in  the  evening  as  possible,  and  be  ready  to  help  fill  out  the 
following  "Record"  from  which  much  concerning  the  moon  and  its 
motions  may  be  learned  :  — 


DATE 

HOUR- 

SHAPE 

PART  OF 
HEAVENS 

DEGREES  ABOVE 
HORIZON 

APPARENT  TIME 
OF  RISING 
(OR  SETTING) 

— 

— 

— 

— 

— 

etc..  etc. 


1  See  footnote  of  lesson  on  Temperature  Records.      It  is  readily  apparent, 
too,  that  these  studies  are  best  begun  when  the  moon  is  "new." 


186      LABORATORY   LESSONS   IN  GENERAL  SCIENCE 

This  record  should  be  made  at  intervals  of  two  or  three  days  through- 
out a  month.  If  the  weather  has  been  unfavorable,  continue  the  ob- 
servations for  two  months  or  more.  Observe  the  moon's  appearance 
as  early  in  the  morning,  too,  as  possible. 

1.  On  your  paper  make  a  drawing  to  show  the  shape  of 
the  moon  as  you  saw  it  last.     At  what  hour  and  date  was 
this? 

2.  Hold  at  arm's  length  an  orange  from  which  the  peel 
has  been  removed.     With  the  same  side  toward  you  all  the 
time,1  turn  completely  around  where   you   stand   without 
stepping  to  one  side.     Let  the  revolution  of  the  moon  about 
the  earth  be  thus  represented  in  the  motion  of  the  orange 
around  yourself  as  an  observer. 

Select  some  object  in  the  room  as  a  source  of  illumination 
(the  sun).  Using  the  shell  of  a  half  orange  to  cover  the 
unilluminated  side  of  the  peeled  orange  (always,  of  course, 
on  the  side  opposite  the  light),  note  very  definitely  the  form 
of  the  white  (illuminated)  part  visible  to  you  as  seen  under 
these  several  conditions  :  — 

(a)  When  the  orange  is  held  between  the  eye  and  the 
object  representing  the  sun. 

(6)  When  it  is  moving  through  the  first  quarter  of  its 
circular  path. 

(c)  At  the  end  of  this  quarter. 

(d)  When  moving  through  the  second  quarter. 

(e)  At  the  end  of  the  second  quarter,  and  opposite  the 
sun. 

(/)  When  moving  through  the  third  quarter. 
(g)  At  the  end  of  the  third  quarte*r. 

1  One  side  of  the  moon  is  always  away  from  the  earth,  and  a  large  part 
of  that  side  is  never  visible  from  any  part  of  the  earth  at  any  time. 


THE   EARTH   AS   A    PLANET  187 

North. 


South, 

FIG.  83.  —  The  successive  changes  in  appearance  (phases)  of  the 
moon  during  a  month. 


188      LABORATORY  LESSONS   IN   GENERAL   SCIENCE 

(h)  When  moving  through  the  fourth  quarter,  and  in 
conjunction  with  the  $un,  i.e.,  in  line  with  it. 

Now  make  a  series  of  eight  drawings  to  show  these  forms 
(phases)  of  the  moon.  (Represent  the  outline  form  of  the 
moon  as  a  circle,  and  blacken  the  unilluminated  part.) 

(b)  Questions  on  the  Data  Gathered 

1.  When  the  moon  was  seen  in  the  west  in  the  early 
evening,  state  (a)  in  what  direction  it  was  from  the  sun ;  (b) 
in  what  direction  with  respect  to  the  sun  its  "horns"  (cusps) 
pointed ;    (c)  what  was  the  shape  of  its  east  edge,  and  what 
of  its  west  edge ;   (d)  what  was  true  of  its  distance  from  the 
west  horizon  (and  the  sun)  evening  after  evening  at  sunset ; 
(e)  its  times  of  setting  night  by  night;    (/)  the  direction  it 
was  from  an  observer  when  it  appeared  as  a  "half  moon" 
at  sunset ;    (g)  how  many  degrees  (or  what  fraction  of  a  cir- 
cle) the  half  moon  is  from  the  sun. 

2.  Of  the  full  moon,  state  (a)  at  what  time  it  rises  with 
reference  to  the  time  of  sunset;    (b)  what  part  of  a  whole 
circle  of  the  heavens  it  is  from  the  sun ;   (c)  how  long  since 
the  moon  was  "new,"  and  how  long  since  it  was  a  half 
moon;    (d)  what  is  true  of  the  times  of  rising  night  after 
night ;    (e)  how  long  from  one  full  moon  to  the  next ;   (/) 
which  quarter  of  the  moon's  revolution  has  been  completed 
when  it  is  full. 

3.  From  observations  of  the  moon  made  mornings  before 
daylight,  state  (a)  the  changes  in  phase  morning  after  morn- 
ing;   (b)  the  direction  of  the  moon  from  the  sun;    (c)  its 
distance  from  the  sun  morning  by  morning ;   (d)  what  must 
result. in  the  course  of  several  davs  as  to  the  direction  of 


THE  EARTH   AS   A    PLANET  189 

sun  and  moon  from  the  observer ;  (e)  through  which  quarter 
of  its  revolution  about  the  earth  the  moon  must  have  passed 
when  seen  in  the  morning  as  a  half  moon;  (/)  to  which 
phase  the  moon  comes  at  the  end  of  the  fourth  quarter; 
(g)  why  the  moon  is  not  then  to  be  seen  for  a  time. 

4.  With  the  moon  full  and  rising  at  sunset,  what  is  the 
position  of  the  earth  with  reference  to  the  sun  and  moon? 
At  time  of  "dark  moon,"  which  side  of  the  moon  as  lighted 
by  the  sun  is  towards  us?     What  kind  of  a  body  must  the 
moon  be  with  reference  to  giving  off  light  of  its  own? 

5.  When  the  moon  was  new,  what  was  its  place  of  setting 
relative  to  that  of  the  sun?     What  was  true  in  this  respect 
when  the  moon  was  full? 

6.  How  many  full  moons  may  there  be  in  a  year?    Ac- 
count for  the   "months"  of  our  calendar.     Ascertain  the 
relation  of  the  date  for  Easter  in  any  year  to  the  time  of  full 
moon  then. 

TIME  AND  TIME-KEEPING,   AND  STANDARD  TIME 

1.  With  a  string  and  any  suitable  weight  arranged  to 
swing  freely  from  a  fixed  point  of  support  as  a  pendulum, 
and  with  the  length  from  the  point  of  support  to  the  center 
of  bob  about  25  inches,  set  the  pendulum  swinging  through 
a  small  arc,  and  count  the  number  of  oscillations  per  minute. 
Repeat,  with  the  pendulum  length  (a)  less;    (b)    greater. 
Upon  what  does  the  time  for  one  oscillation  seem  to  depend  ? 

2.  Make  the  pendulum  length  now  36  inches,  and  count 
the  number  of  oscillations.     Find  the  ratio  value  to  two 
decimal  places  (a)  of  the  numbers  of  oscillations  for  the  two 


190      LABORATORY  LESSONS  IN   GENERAL  SCIENCE 

pendulums;    (6)  of  the  square  roots  of  the  two  pendulum 
lengths.     [Use  smaller  number  for  divisor  in  both  cases.] 

3.  Make  the  pendulum  length  39+  inches,  and  count  the 
oscillations  per  minute. 

4.  With    a    stronger    force    pulling    the 
pendulum  down,  what  would   probably  be 
true  (a)  of  the  rate  of  motion  of  the  pendu- 
lum ;     (b)  of  the  number  of  oscillations  per 
minute?     Since  the  force  of  gravity  varies 
in  different  latitudes,  what  must  be  true  of 
the  lengths  of  pendulums  to  make  the  same 
number  of  oscillations  per  minute  in  differ- 
ent localities?     What  must  be  true  of  the 
lengths  of  second's  pendulums  in  different 
places  ? 

5.  Recall     the     effect     of     temperature 
changes   (heat  and    cold)   upon  lengths  of 
bodies.     What  must  be  true  of  the  pendu- 

\J  lum  length  in  the  same  clock  (a)  summer 

and   winter;     (6)    through   a   day?     What 
FIG.  84. — A  clock    effect  has  this  on  the  time  for  one  oscillation 
escapement.         of  Q^  pen(julum  ?     What  means  are  em- 
ployed  to  secure  uniform  oscillation  periods  for  the  same 
pendulum  ? 

6.  Secure  an  old  clock  from  which  the  dial  has  been 
removed.  Find  the  number  of  oscillations  that  allow  one 
tooth  of  the  wheel  to  pass  the  escapement.  Count  the  teeth 
of  this  wheel.  Calculate  the  number  of  oscillations  for  every 


THE  EARTH   AS   A    PLANET  191 

one  turn  of  this  wheel.  From  the  number  of  oscillations  per 
minute  of  the  pendulum  (by  your,  watch),  determine  the 
time  required  for  one  turn  of  this  wheel. 

By  counting  the  number  of  teeth  of  the  pinion  of  this 
same  wheel  and  of  the  second  wheel  into  which  the  pinion 
works,  calculate  the  time  for  one  turn  of  this  second  wheel. 
In  case  a  hand  were  attached  to  the  axle  of  this  second  wheel, 
what  time  interval  would  be  counted  off  by  its  every  com- 
plete turn?  What  purpose  has  a  portion  at  least  of  the 
wheelwork  of  a  clock? 

7.  Note  the  result  as  the  escapement  at  the  upper  end  of 
the  pendulum  is  pulled  forward  by  the  teacher  sufficiently 
to  free  the  first  wheel  in  the  train,  and  the  effect  of  replacing 
the  escapement  on  the  rate  of  the  wheel  motion.     State  (a) 
the  cause  of  the  motion  in  the  wheelwork;    (6)  the  use  of 
the  pendulum  with  reference  to  such  rate  of  motion.     Re- 
call what  was  true  after  a  time  of  the  motion  of  the  pen- 
dulum in  paragraph  1 .     What  is  true  of  the  motion  of  a  clock 
pendulum?     Explain  the  difference.     Name  another  use  of 
the  wheelwork  of  a  clock.     What  is  the  sole  purpose  of  the 
pendulum  in  the  clock  ? 

8.  Calculate  the  number  of  seconds  in  a  day.     How  is 
the  natural  unit  of  time  we  call  the  day  fixed  for  us  ?     From 
what  time  till  what  time  is  the  true  solar  day  measured? 
Since  in  a  day  there  are  86,400  seconds,  what  will  be  true  of 
the  relative  lengths  of  these  equal  parts  if  the  day's  length 
varies  during  the  year  (as  it  does)  ? 

9.  With  86,400  swings  of  a  second's  pendulum  counting 
off  a  day-period,  what  will  be  true  of  noon  by  the  clock, 
and  noon  by  true  solar  time  (meridian  passage  of  sun)  ? 


192      LABORATORY   LESSONS   IN   GENERAL  SCIENCE 

This  difference,  amounting  at  different  times  of  year  to 
values  varying  from  0  seconds  to  about  16  minutes,  is  the 
"equation  of  time  "  (or  the  "sun  fast,"  "sun  slow")  of  the 
almanacs.  It  must  be  taken  into  account  in  comparing 
clock  time  and  sun  time.  Clock  or  "local"  noon  is  deter- 
mined from  true  noon  by  adding  (or  subtracting)  the  equa- 
tion of  time  for  what  particular  date  ? 

10.  What  is  true  of  noon  local  time  for  you  and  for  places 
(a)  eastward;  (6)  westward?  What  will  be  true  of  the 


STANDARD  TIME  IN  THE  UNITED  STATES 

FIG.  85. 

watch  readings  of  people  keeping  local  time  in  towns  east 
and  west  of  one  another  ?  What  is  meant  by  standard  time  ? 
With  the  sun  neither  slow  nor  fast,  by  what  amount  will  a 
clock  that  keeps  standard  time  vary  from  the  true  local 
time? 


XVII.  THE  HEAVENS 

1.  Write  the  names  of  several  stars  known  to  you.    Tell 
in  what  way  you  recognize  any  one  of  these  when  seen. 

2.  Write  the  names  of  several  groups  of  stars  (constel- 
lations) known  to  you.     Represent  on  your  paper  the  ar- 
rangement of  the  brighter  stars  in  any  one  of  these  groups, 
thus  showing  the  form  by  which  it  can  be  recognized  and 
pointed  out  to  anyone  else. 

3.  The  stars  are  supposed  to  be  bodies  much  like  the  sun, 
and  many  of  them  vastly  larger.     What  is  the  explanation 
for  their  apparent  smallness,  and  their  lack  in  heat  and 
light  ?    When  only  are  stars  to  be  seen,  and  why  so  ?    What 
is  the  number  of  the  stars? 

4.  At  what  season  of  the  year  do  the  stars  generally 
seem  to  be  brightest?    What  is  true  of  the  amount  of 
water  vapor  present  in  the  atmosphere  then?     What  com- 
monly is  the  cause  of  any  haze  overcasting  the  sky,  dim- 
ming  the   light  of   the  stars  or  hiding   them   altogether? 
What  differences  are  there  in  the  appearance  of  stars  other 
than  brightness? 

5.  What  significance  has  the  rising  and  setting  of  stars, 
i.e.,  what  occasions  it?     What  is  the  real  name  of  the  so- 
called  "shooting  stars"?    What  is  their  nature? 

6.  After  some  sufficient  time   (which  the  weather  and 
other  conditions  will  determine),  be  prepared  from  obser- 

.  o  193 


194     LABORATORY  LESSONS   IN  GENERAL  SCIENCE 

vations  made  by  you  (either  with  or  without  assistance)  to 
write  answers  to  the  following  requirements :  — 

(a)  Whether  the  path  of  any  star  (or  constellation)  across 
the  sky  night  after  night  is  always  the  same. 

(6)  What  is  true  of  the  places  of  rising  (or  setting)  of  the 
same  star  night  after  night. 


FIG.  86.  —  Polar  constellations. 


(c)  The  names  of  several   constellations   always   above 
horizon  (that  never  "set")  to  observers  in  your  latitude. 

(d)  The  appearance  of  the  Milky  Way.     Its  place  in  the 
sky  relative  to  some  known  constellations.     Its  real  nature. 


THE   HEAVENS 


195 


(e)  A  diagram  (at  board,  or  on  paper)  showing  the  form 
of  the  "Big  Dipper,"  and  its  position  relative  to  the  North 
Star. 

(/)  If  any  change  occurs  in  the  brightness  of  the  same 
star  night  after  night,  aside  from  effects  of  atmospheric 
conditions. 

7.  From  books  and  other  sources  secure  information  on 
the  following  topics :  — 

(a)  The  names  of  the  eight  planets  of  our  solar  system 
in  order  of  their  distances  from  the  sun. 


O 

MERCURY 


O 

VENUS 


O 

EARTH 


O 

MARS 


FIG.  87.  —  Relative  sizes  of  the  planets. 

(6)  The  distinctions  between  star  and  planet  as  to  their 
sources  of  light,  and  their  physical  states. 

(c)  A  diagram  to  show  the  relative  sizes  of  the  planets. 


196      LABORATORY  LESSONS   IN  GENERAL  SCIENCE 


(d)  A  diagram  to  show  the  relative  distances  of  the  planets 
from  the  sun. 


i 


I    --«7 

*--.ae 


•--VU.ouo.ooo 


2,775,000,000--' 


FIG.  88.  —  Distances  of  the  planets  from  the  sun. 


(e)  The  views  concerning  the  universe  held  by  the  ancients. 
The  knowledge  Columbus  had  of  the  earth's  size  and  form. 

\ 


FIG.  89.  —  Periods  of  revolution  of  the  planets  (length  of  their  years). 

(/)  The  distance  from  sun  to  earth.     The  time  required 
for  light  to  traverse  that  distance.     The  time  required  for 


FIG.  90.  —  It  is  calculated  that  the  earth  receives  about  one  two-billionth 
of  the  heat  and  light  given  off  by  the  sun. 


THE   HEAVENS  197 

light  from  the  nearer  stars  to  reach  the  earth,  and  the  time 
from  the  more  distant  stars.  * 

(g)  The  two  motions  of  the  moon  as  the  earth  moves  on 
around  the  sun  in  its  path  of  revolution.  The  meaning  of 
the  term  satellite  as  applied  to  the  moon. 

(ti)  The  relative  intensity  (degree)  of  heat  and  light  from 
the  sun  upon  Mercury,  Earth,  Neptune. 

(i)  The  length  of  the  years  for  the  different  planets,  i.e., 
their  periods  of  revolution  around  the  sun. 


APPENDIX 

LIST  OF  APPARATUS  AND  SUPPLIES,  AND  THEIR  COST 

Everything  required  in  these  Lessons  as  apparatus  and  supplies 
will  be  found  in  the  equipment  commonly  provided  for  teaching  the 
high  school  sciences.  Good  substitutes  for  many  articles  named  may 
easily  be  arranged.  It  will  always  be  best,  however,  to  have  separate 
supplies  for  the  work  in  General  Science,  and  to  have  them  kept  for 
this  use  only. 

As  a  reference  list  when  purchases  are  to  be  made  it  will  be  found 
convenient  to  note  what  the  Lessons  call  for  as  given  below.  The 
prices  named  are  approximate  only,  and  the  articles  named  may  be 
had  of  any  of  the  supply  and  apparatus  houses.  Articles  commonly  at 
hand  anywhere,  or  readily  obtainable  at  home,  are  not  listed.  Collec- 
tions of  garden  seeds  and  of  grains  may  be  kept  in  small  bottles  prop- 
erly labeled,  and  seeds  of  various  trees  may  be  kept  in  cigar  boxes. 
Such  supplies  are  readily  provided  for  class  use  during  the  year. 

Type  forms  of  leaves  and  roots  and  flowers,  suitably  mounted, 
together  with  exhibits  of  various  rock  and  ore  specimens  on  cardboard 
(securely  sewed  in  place),  are  desirable  additions  to  the  stock  of  sup- 
plies. Some  of  the  large  industries  have  "School  Exhibits,"  which 
may  be  secured  at  nominal  charge ;  these  show  the  various  stages  of 
manufacture  of  raw  materials  into  marketable  products. 

[It  is  to  be  remembered  that  the  books  and  bulletins  listed 
elsewhere  are  considered  an  essential  part  of  the  working 
material  for  these  Lessons.] 

acids :  — 

hydrochloric,  1  lb.,  with  bottle $.25 

nitric,  1  lb.,  with  bottle 30 

sulphuric,  4  Ibs.,  with  bottle 55 

199 


200  APPENDIX 

alcohol,  denatured,  1  quart $     .45 

ammonia,  1  lb.,  with  bottle 30 

balances,  specific  gravity 4.50 

balances,  spring,  64  oz.,  2000  grams,  each 40 

barometer 15.00 

barometer  tube 20 

blast  lamp l    . 3.25 

bleaching  powder,  can 15 

blowpipe,  8-inch 08 

borax,  1  lb 15 

bottles,  wide-mouth,  8  oz 05 

bottles,  screw  cap,  for  seeds  and  grains,  2  oz 06 

burette  clamp,  iron 30 

candles,  small  wax,  per  box 10 

cells,  dry,  each .25 

cells,  simple  voltaic 50 

chimneys,  student-lamp 06 

compass,  magnetic,  2-inch 30 

connectors,  double,  for  battery  wires 10 

diffusion  shells,  100  X  16  mm. 25 

electric  bell,  2£-inch 40 

ether,  1  oz 10 

evaporating  dishes,  3-inch 15 

Fehling's  solutions,  1  oz.  each 15 

file,  triangular,  6-inch 10 

filter  paper,  pkg.  of  100,  10  cm 10 

funnel,  3^-inch 14 

glass  cutter,  5  wheel 30 

glass  jar  (\  gallon  battery  jar) 20 

glass  plates,  blue  and  red,  each  2"  X  3" 05 

glass  tubing,  ^-inch,  5  Ibs 2.00 

graduate,  100  c.c > 50 

iodine  solution,  2  oz 20 

1  Some  means  must  be  provided  for  heat  in  case  the  room  for  General 
Science  does  not  have  gas  burners.  A  plumber's  torch  is  very  satisfactory. 
Pipettes  and  elbow  tubes  may  then  be  made  as  needed  from  glass  tubing. 


APPENDIX  201 

jug,  one  gallon $  .35 

labels,  box 08 

lever  holders 30 

limewater  (to  be  made) 

litmus  paper,  sheets,  red  and  blue,  each      . 04 

magnets,  bar,  in  box,  per  pair,  6-inch .45 

magnet,  electro-,  3-inch 1.25 

magnifiers,  watchmaker's 40 

mercury,  1  lb.,  in  bottle 1.50 

metric  (foot)  rules,  1  dozen 35 

meter  stick,  brass  tips 35 

mirror,  plane,  6-inch  strips 10 

mortar,  3-inch 36 

paraffine,  1  lb .         .16 

potassium  chlorate,  1  lb .35 

prism,  equilateral,  3-inch 25 

protractors,  manilla  card .06 

pulleys,  triple-tandem,  pair 2.25 

pumps,  glass  models,  lift  and  force 2.65 

ringstand,  2  rings,  18-inch 40 

rubber  stoppers,  — 

one -hole  for  test  tubes 03 

two-hole  for  wide-mouth  bottles 12 

rubber,  thin  sheet,  per  sq.  ft 30 

rubber  tubing,  TVmch,  12  ft 75 

shears,  common,  5-inch 50 

sodium  bicarbonate,  1  lb .         .10 

sodium  carbonate,  1  lb 10 

sphere  (toy  globe) 10 

spoons,  iron,  tea,  per  doz 25 

sugar,  grape  (glucose),  1  lb .10 

telegraph  key 1.15 

telegraph  sounder 2.00 

test  tubes,  6  X  f  inch,  per  dozen 25 

test  tube  brush 05 

test  tube  rack,  wood 25 


202  APPENDIX  - 

thermometer,  chemical,  C.  &  F $  .§0 

thistle  tube 08 

vaseline,  bottle 05 

weights,  metric,  set,  1  to  500  grams 1.75 

weights,  metric,  fractional,  each 05 

wire,  copper,  No.  22,  insulated,  |  Ib 30 

wire  gauze,  asbestos  center,  5"  X  5" 09 

wire,  iron,  No.  24,  annealed,  4  oz 16 

wire  pliers,  side-cut,  6-inch 70 


A  LIBRARY  LIST  OF  REFERENCE  BOOKS 

Books  should  be  considered  tools  for  the  use  of  pupils. 
To  learn  to  use  them  aright  is  fundamental  in  school  work, 
and  one  of  its  chief  aims.  Knowing  where  to  find  needed 
information,  coupled  with  a  desire  for  knowledge,  constitutes 
no  small  part  of  an  education.  In  the  books  listed  below, 
there  is  provided  a  fund  of  information  on  the  topics  of  these 
Lessons  that  is  worthy  the  best  efforts  of  every  pupil. 

One  book  generally  suffices  as  a  text  in  any  subject  in 
school  work.  But  in  General  Science  no  one  book  is  likely 
to  provide  all  the  material  that  very  properly  comes  under 
discussion.  In  some  cases  it  may  be  desirable  to  have 
several  copies  of  the  less  expensive  books  where  these  are 
of  superior  worth  and  usefulness.  For  class  instruction 
this  is  often  wiser  than  to  make  the  same  outlay  for  single 
copies  of  all  the  books  named.  To  have  the  use  of  only 
one  book  in  General  Science,  however  valuable  the  results 
attained  may  be,  is  to  suffer  somewhat  the  same  limitations 
as  does  the  carpenter  who  for  tools  has  but  a  jackknife. 
The  skilled  mechanic  selects  from  his  large  assortment  that 
particular  tool  best  suited  to  his  purpose. 


APPENDIX  ,         203 

Teaching  conditions  may  render  impossible  any  extended 
use  of  reference  books,  but  no  apology  is  needed  for  having 
provided  a  generous  reference  list.  The  use  of  these  books 
and  others  of  like  character  will  enrich  the  course.  While 
library  equipment  and  the  preferences  of  instructors  may 
make  desirable  many  substitutions  in  any  list  named,  it  is 
urged  that  the  greatest  care  be  exercised  in  the  selection 
of  references. 

Where  a  double  period  for  daily  laboratory  and  class 
work  is  arranged,  no  lesson  preparation  outside  those  hours 
will  be  necessary.  In  addition  to  recitation  and  experi- 
mental work  there  is  in  this  arrangement  an  opportunity 
under  favorable  conditions  to  teach  pupils  how  to  study, 
and  to  direct  their  desire  for  knowledge  along  lines  that  offer 
the  largest  educational  values. 

Bailey  (Mac.),  Sanitary  and  Applied  Chemistry $1.40 

Bengtson  &  Griffith  (Mac.),  The  Wheat  Industry 65 

Bigelow  (Mac.),  Applied  Biology 1.40 

Blakeslee  &  Jarvis  (Mac.),  Trees  in  Winter 2.00 

Brownell  (T.  P.),  Lessons  in  Physics 75 

Brownell  (T.  P.),  Lessons  in  Chemistry 50 

Caldwell  &  Eikenberry  (G.),  General  Science '.80 

Clark  (Am.),  Introduction  to  Science 1.20 

Coleman  (Mac.),  Hygienic  Physiology 60 

Coleman  (Mac.),  The  People's  Health    ...  .70 

Conn  (G.),  Bacteria,  Yeasts,  and  Molds 1.00 

Coulter,  J.  G.  (Am.),  Plant  Life,  and  Plant  Studies  1.20 

Coulter  &  Patterson  (Ap.),  Practical  Nature  Study      ....       1.35 
Crawford  (Hi.),  Nature  Study  Lessons       ...  .75 

Doty  (Ap.),  Prompt  Aid  to  the  Injured      .     .  1.50 

Freeman  &  Chandler  (G.),  World's  Commercial  Products     . 

Goff  (Co.),  Principles  of  Plant  Culture       1.00 

Harper  (Mac.),  Animal  Husbandry  for  Schools 1.40 


204  APPENDIX 

Harrington  (Ap.),  About  the  Weather $  .60 

Hessler  (San.),  First  Year  of  Science 1.25 

Hooker  (Am.),  Child's  Book  of  Nature,  Part  III 50 

Jewett  (G.),  The  Next  Generation  .75 


Kinne  &  Cooley  (Mac.),  Foods  and  Household  Management     . 
Lipman  (Mac.),  Bacteria  in  Relation  to  Country  Life       .     .     . 

Parloa  (Cen.),  Home  Economics 

Price  (Wi.),  Handbook  on  Sanitation 

Price  (Sm.),  The  Land  We  Live  In    . 


.10 
.50 
.00 
.50 
.50 

Rowell  (Mac.),  Introduction  to  General  Science 75 

Snell  (Mac.),  Elementary  Household  Chemistry 1.25 

Snyder  (Mac.),  Chemistry  of  Plant  and  Animal  Life    ....       1.50 

Tarr  (Mac.),  New  Physical  Geography       ........       1.00 

Tarr  &  McMurry  (Mac.),  New  Geography,  Second  Book      .     .       1.10 

Warren  (Mac.),  Elements  of  Agriculture 1.10 

Williams  &  Fisher  (Mac.),  Elements  of  Theory  and  Practice 

of  Cookery 1.00 

Wilson  &  Warburton  (Web.),  Field  Crops       1.50 

The  free  use  of  high  school  science  texts  serves  many 
excellent  ends.  Aside  from  the  information  for  immediate 
use  furnished  by  them  in  a  concise,  attractive,  and  reliable 
form,  pupils  with  active  minds  will  scarcely  fail  to  find  in 
some  one  of  these  fields  of  science  that  which  will  arouse  a 
desire  to  go  beyond  a  course  in  general  science.  Texts  and 
manuals  in  Agriculture,  Botany,  Chemistry,  Geology,  Home 
Economics,  Meteorology,  Physics,  Physical  Geography, 
Zoology,  etc.,  should  have  extended  use  as  reference  books 
in  connection  with  General  Science. 

The  publishers  of  the  books  listed  above  are  as  follows :  — 
(Mac.)  The  Macmillan  Company  :  New  York. 
(Ap.)  Appleton  &  Co. :  New  York. 
(G.)  Ginn  &  Co. :  Boston. 
(Am.)  American  Book  Co. :  New  York. 
(Wi.)  Wiley  &  Sons  :  New  York. 


APPENDIX  205 


(Hin.)  Hinds,  Noble  &  Eldredge :  New  York. 
(Cen.)  Century  Company  :  New  York. 
(T.  P.)  The  Torch  Press :  Cedar  Rapids,  la. 
(Co.)  Co-operative  Company :  Madison,  Wis. 
(Sin.)  Small,  Maynard  &  Co. :  New  York. 
(San.)  Benj.  Sanborn  &  Co. :  New  York. 
(Web.)  Webb  Publishing  Co. :  St.  Paul,  Minn. 


LIST  OF  BULLETINS 
U.  S.  DEPARTMENT  OF  AGRICULTURE,  WASHINGTON,  D.C. 

Farmers'  Bulletins1 
No. 

54  Some  Common  Birds. 

55  The  Dairy  Herd. 

106  Breeds  of  Dairy  Cattle. 

128  Eggs,  and  Their  Uses  as  Food. 

134  Tree  Planting  on  Rural  School  Grounds. 

157  The  Propagation  of  Plants. 

173  Primer  of  Forestry,  Part  I. 

181  Pruning. 

183  Meat  on  the  Farm. 

218  The  School  Garden. 

245  Renovation  of  Worn-out  Soils. 

249  Cereal  Breakfast  Foods. 

255  The  Home  Vegetable  Garden. 

266  Management  of  Soils  to  Conserve  Moisture. 

1  Order  through  the  Congressman  from  your  district.  It  will  be  well  to 
have  several  copies  each  of  some  of  these  Bulletins.  All  give  valuable 
information  in  form  available  for  teaching.  One  of  the  purposes  of  their 
publication  is  school  use.  No  charge  is  made  for  them. 

It  is  suggested  that  provision  be  made  for  the  proper  care  of  all  Bulle- 
tins from  their  first  use.  One  good  way  is  to  bind  them  more  or  less  durably 
into  sets  of  related  titles,  with  labels  giving  the  bulletin  numbers  and  names 
in  each  set,  and  then  as  needed  these  sets  can  be  put  out  for  use  protected 
by  covers  such  as  are  used  with  magazines  in  public  reading  rooms. 


206  APPENDIX 

No. 

270  Modern  Conveniences  for  the  Farm  Home. 

287  Poultry  Management. 

293  Use  of  Fruit-  as  Food. 

298  Food  Value  of  Corn  and  Corn  Products. 

345  Some  Common  Disinfectants. 

355  A  Successful  Poultry  and  Dairy  Farm. 

358  Primer  of  Forestry,  Part  II. 

363  The  Use  of  Milk  as  a  Food. 

369  How  to  Destroy  Rats. 

375  Care  of  Food  in  the  Home. 

377  Harmfulness  of  Headache  Powders. 

389  Bread  and  Bread-Making. 

393  Habit  Forming  Agents. 

413  The  Care  of  Milk,  and  its  Use  in  the  Home. 

447  Bees. 

450  Facts  about  Malaria. 

463  The  Sanitary  Privy. 

473  Tuberculosis. 

475  Ice  Houses. 

478  How  to  Prevent  Typhoid  Fever. 

491  Profitable  Management  of  Small  Apple  Orchards. 

492  The  More  Important  Insect  and  Fungous  Enemies  of  the  Apple. 

493  The  English  Sparrow  as  a  Pest. 
607  The  Farm  Kitchen  as  a  Workshop. 
617  School  Lessons  on  Corn. 

630    Some  Common  Birds  Useful  to  the  Farmer. 
679    House  Flies. 

Bulletin  100,  Bureau  of  Chemistry $0.10 

Circular  125,  Bureau  of  Animal  Industry 0.10 

Circular  19,  Division  of  Publications Free 

(A  list  of  the  Publications  of  the  Department  of  Agriculture  Classified 
for  Teachers.) 
Circular  29  on  Stock  Judging,  Purdue  University :   La  Fayette,  Ind. 

(Agricultural  Extension)        $0.10 

Board  of  Health  of  your  State,  —  Rules  and  Regulations     .     .       Free 


APPENDIX  207 

REFERENCES  FOR  CLASS  ASSIGNMENTS1 

1.   THE  HUMAN  BODY 

1.  The  hand  —  Bigelow,  pp.  519-522;   Coleman  (Physiology),  pp.  16- 

23;  Crawford,  pp.  14-17. 

2.  The  mouth  —  Bigelow,  pp.  465-468 ;    Coleman  (Health),  pp.  109- 

113;   Coleman  (Physiology),  pp.  102-103,  152-157,  243. 

3.  The  eye  —  Bigelow,  pp.  515-518;    Crawford,  pp.  5-7;    Coleman 

(Physiology),  pp.  248-255. 

II.   HEAT  IN  RELATION  TO  THE  HUMAN  BODY 

1.  Combustion  —  Brownell    (Chemistry),   pp.     13-14,    34-38.     (Any 

good  text  in  Chemistry.) 

2.  Ventilation  —  Price,  pp.  15-41.  , 

3.  Respiration  —  Bigelow,  pp.  110-114,  502-506,  526-528;  Coleman 

(Physiology),  pp.  104-121 ;  Coleman  (Health),  pp.  20-41 ;  Doty, 
pp.  170-177. 

4.  The  human  body  as  an  engine  —  Bigelow,  pp.  492-499 ;   Coleman 

(Physiology),  pp.  138-141. 

5.  Regulation  of  body  temperature  —  Bigelow,  pp.  522-524,  533-555. 

III.   HEALTH  AND  WELL-BEING 

1.  Keeping    well  —  Coleman    (Physiology),    pp."  201-214;     Coleman 

(Health),  pp.  1-8. 

2.  Infection  —  Bigelow,  pp.   276-297,   554-560;    Coleman    (Health), 

pp.  11-19,  114-130;  Coleman  (Physiology),  pp.  122-132,  267; 
Conn,  pp.  100-138,  203-266;  Doty,  pp.  91-111 ;  Farmers'  Bulletin, 
No.  345 ;  Lipman,  pp.  1-25 ;  Price,  pp.  269-285 ;  Regulations  of 
the  State  Board  of  Health. 

3.  Sanitation  —  Bailey,  pp.  106-116;  Coleman  (Health),  pp.  190-214; 

Lipman,  pp.  56-98;  Bulletin  100,  Bureau  of  Chemistry,  U.  S. 
Dept.  of  Agriculture,  pp.  8-1 1 ;  Farmers'  Bulletins,  Nos.  270, 
375,  478. 

1  Make  free  use  of  any  good  texts  in  General  Science  for  all  these  lessons. 
Use  the  Index  of  any  text  to  find  the  desired  information  quickly.  If  one 
text  does  not  have  what  is  wanted,  consult  another. 


208  APPENDIX 

4.  The  water  supply   and   health  —  Coleman    (Health),   pp.   42-55; 

Price,  pp.  46-52. 

5.  General  health  problems  —  Bailey,  pp.  79-91,  297-307;    Bigelow, 

pp.  312-314,  393-397;  Coleman  (Health),  pp.  74-92, 132-152,  217- 
260;  Conn,  pp.  139-181;  Doty,  pp.  203-219;  Lipman,  pp.  103- 
134,431-446;  Price,  pp.  54-71 ;  Circular  125,  Bureau  of  Animal 
Industry,  U.  S.  Dept.  of  Agriculture ;  Farmers'  Bulletins,  Nos.  345, 
369,  450,  459,  473.  (Various  Bulletins  from  the  State  Board  of 
Health.) 

6.  Life,  growth,  rest,   and  recreation  —  Bigelow,  pp.   13-21,  44-57, 

122-126;  Coleman  (Health),  pp.  8-11,  153-163;  Coleman  (Phys- 
iology), pp.  1-13. 

7.  Stimulants  and  narcotics  —  Bailey,  pp.  257-287 ;  Bigelow,  pp.  539- 

554;  Coleman  (Physiology),  pp.  27,  100,  151,  180,  214-237;  Cole- 
man (Health),  pp.  164-176;  Farmers'  Bulletins,  Nos.  377,  393; 
Jewett,  pp.  118-125,  136-152. 

8.  General  science  and  right  living  —  Jewett,  pp.  1-6,  126-135,  153- 

188 ;  Warren,  pp.  5-35. 

IV.  MATTER  AND  FORCE 

1.  Some  properties  of  matter,  and  changes  in  matter  due  to  force  — 
Brownell  (Physics),  pp.  9-14,  19-23,  107-109.  (Any  good  text  in 
Physics.) 

V.  WATER,  AND  ITS  USES 

1.  Some  properties  of  water  —  Crawford,  pp.  173-182;   Hooker  (Part 

III),  Chaps.  XV-XXI. 

2.  Vaporization  and  condensation  —  Coulter  &  Patterson,  pp.  235- 

240;  Harrington,  pp.  66-98;  Tarr,  pp.  244-250. 

3.  Heat  of  vaporization,  and  of  fusion  —  (Any  good  text  in  Physics.) 

4.  Solution,  absorption,  diffusion  —  Brownell  (Physics),  pp.  20-22,  109. 

(Any  good  text  in  Physics.) 

5.  Osmosis  in  the  human  body  and  in  plants  —  Bigelow,  pp.  88-97. 

6.  Study  of  a  stream. 

7.  Valley  formation,  and  surface  erosion  —  Crawford,  pp.   145-149; 

Tarr,  pp.  50-68. 


APPENDIX  209 

VI.   THK  ATMOSPHERE 

1.  Some  properties  ami  uses  of  air  —  Hooker  (Part  III),  Chnps.  F,  II, 

IV,  VI,  X -XIV;  Tarr,  pp.  229-230. 

2.  Pressure  exerted  by  the  atmosphere  —  (Any  good  text  in  Physics.) 

3.  Applications   of   atmospheric   pressure  —  Brownell    (Physios),   pp. 

54-59,  114-115;   Hooker  (Part  III),  Chaps.  V,  VI'. 

4.  Causes  of  change  in  atmospheric  pressure. 

5.  Currents  in  the  atmosphere  —  Harrington,  pp.  48-59 ;    Tarr,  pp. 

255-262. 

(>.    Areas  of  high  and  low  pressure  —  Harrington,  pp.  99-127 ;  Tarr,  pp. 
262-271. 

VII.   WEATHER  AND  CLIMATE 

1.  Weather  in  the  affairs  of  men  —  Harrington,  pp.  1-32,  187-222; 

Lipman,  pp.  52-55;  Tarr,  pp.  83-89,  105-108,  275-279,  369-392. 

2.  Weather  as  affected  by  highs  and  lows  —  Harrington,  pp.  128-135, 

142-165 ;   Tarr,  pp.  285-293,  426-427. 

3.  The  thermometer  —  (Any  good  text  in  Physics.) 

4.  Temperature  records. 

5.  Solar  heating  —  Crawford,  pp.  182-184. 

6.  General  weather  records. 

VIII.  AT  OUR  HOMES 

1.  Rooms  of  the  house,  and  their  furnishings  —  Bailey,  pp.  25-38,  48- 

60;  Coleman  (Health),  pp.  177-190;  Farmers'  Bulletins,  Nos.  270, 
463,  475,  607;  Kinne  &  Cooley  (Foods),  15-53,  265-277,  352-364; 
Parloa,  pp.  1-26,  35-167,  268-278;  Price,  pp.  72-113;  Snell,  pp. 
59-81;  Williams  &  Fisher,  pp.  11-23,  31-49.  (Trade  catalogues 
giving  cuts  of  heating  system's  and  plumbing  outfits.) 

2.  Cost  of  living  —  Bailey,  pp.  308-321 ;   Coleman  (Health),  pp.   93- 

108;  Coleman  (Physiology),  pp.  166-179;  Farmers' Bulletin,  No. 
375;  Kinne  &  Cooley  (Foods),  pp.  54-83,  278-294,  321-331,  342- 
351;  Parloa,  pp.  168-201,222-261;  Price,  pp.  187-202;  Williams 
&  Fisher,  pp.  73-82,  136-191,  226-247.  (State  Food  Laws,  and 
Regulations  of  the  State  Board  of  Health.) 

3.  Fires,  and  burns  —  (Bulletins  of  the  State  Fire  Warden,  and  regu- 

lations of  the  local  fire  officials.) 


210  APPENDIX 

4.  Accidents  other  than  burns  —  Coleman  (Health),  pp.  299-302; 
Coleman  (Physiology),  p.  266;  Doty,  pp.  148-151,  182-202. 
(Bulletins  from  the  State  Commissioner  of  Labor,  as  well  as  from 
local  labor  officials.) 

IX.  HOUSEHOLD  CHEMISTRY 

1.  A  review  of  some  chemical  changes. 

2.  The  chemistry  of  cleaning  —  Bailey,  pp.  92-105 ;   Kinne  &  Cooley 

(Foods),  pp.  365-378;    Parloa,  pp.  300-311;    Snell,  pp.  105-113, 
121-126,  143-161,  243-253.     (Any  good  text  in  Home  Economics.) 

3.  Acids,  bases,  and  salts  — Snell,  pp.  82-104,  114-120.     (Any  good 

text  in  chemistry.) 

4.  Some  carbonates.     (Any  good  texts  in  Chemistry,  and  Geology.) 

X.  THE  HOME  SURROUNDINGS 

1.  A  garden  in  the  home  life  of  a  family. 

2.  The  care  of  a  garden  —  Farmers'  Bulletins,  Nos.  218,  255;  Freeman 

&  Chandler,  pp.  254-263;  Goff  (selected  parts).     (Catalogues  of 
some  reliable  houses  dealing  in  flower  and  garden  seeds,  tools,  etc.) 

3.  Tree  planting  —  Farmers'  Bulletins,  Nos.  134,  157,  173,  181,  358, 

468;    Warren,  pp.  216-234.     (Catalogues  of  any  extensive  and 
reputable  Nursery.) 

4.  'Trees  of  the  neighborhood  —  Blakeslee  &  Jarvis,  pp.  195-209  (and 

other  selected  parts) ;  Coulter  &  Patterson,  pp.  162-167 ;  Farmers' 
Bulletin,  No.  468. 

5.  Some  plant  studies  —  Bigelow,  pp.  66-85,   156-231.     (Any    good 

text  in  Botany  or  Plant  Biology.) 

6.  Birds  about  our  homes  —  Bigelow,  pp.  428^36 ;   Coulter  &  Patter- 

son, pp.  112,  122-124,  303-313;    Crawford,  pp.  39-42;   Farmers' 
Bulletins,  Nos.  54,  493,  630. 

XL  LOCAL  INDUSTRIES 

1.  Some  occupations  of  the  community. 

2.  Modern  industrial  life  —  Tarr-McMurry,  New  Geography,  Second 

Book  (selected  parts). 


211 

3.   Sanitary  conditions  for  the  wage  earner.  —  Jevvett,  pp.   189-195 ; 
Price,  pp.  151-186. 

XII.  THE  FARM,  AND  OUR  FOOD  SUPPLIES 

1.  The  hen  —  Crawford,  pp.  35-38. 

2.  Eggs  —  Bigelow,  pp.  58-64 ;    Farmers'  Bulletin,  No.  128 ;    Harper, 

pp.  378-381. 

3.  Poultry  keeping  —  Farmers'  Bulletins,  Nos.  128,  287,  355;   Harper, 

pp.  307-348;   Warren,  pp.  368-371. 

4.  The  horse  — Harper,  pp.  3-102,  349;  Jewett,  pp.  34-42 ;  Circular  29, 

Experiment  Station,  Purdue  University. 

5.  Cows   and   the   dairy  industry  —  Bailey,    pp.    228-237,   242-256; 

Coleman  (Health),  pp.  56-73 ;  Conn,  pp.  182-202 ;  Crawford,  pp. 
27-33 ;  Farmers'  Bulletins,  Nos.  55,  106,  183,  363,  413 ;  Harper, 
pp.  105-194 ;  Lipman,  pp.  357-430 ;  Price,  pp.  203-268 ;  Warren, 
pp.  323-350;  Williams  &  Fisher,  pp.  92-101,  291-295;  Circular 
125,  Bureau  of  Animal  Industry;  Circular  29,  Experiment 
Station,  Purdue  University. 

6.  Some  foodstuffs  —  Bailey,  pp.  128-206 ;  Farmers'  Bulletin,  No.  389 ; 

Kinne  &  Cooley  (Foods),  pp.  138-157,  209-246;  Williams  & 
Fisher,  pp.  59-71,  102-135,  259-262. 

7.  Lessons  on  corn  —  Bigelow,  pp.  149-151 ;   Farmers'  Bulletins,  Nos. 

298,  617;  Freeman  &  Chandler,  pp.  50-58,  65;  Warren,  pp.  156- 
178;  Wilson  &  Wai-burton,  pp.  47-131. 

8.  Apple  raising  as  an  industry  —  Conn,  pp.  40-52 ;    Farmers'  Bulle- 

tins, Nos.  293,  491,  492;  Freeman  &  Chandler,  pp.  263-278; 
Kinne  &  Cooley  (Foods),  pp.  87-108;  Warren,  pp.  248-270. 

9.  Wheat,  and  wheat  growing  —  Bengtson  &  Griffith  (selected  parts); 

Freeman  &  Chandler,  pp.  1-20;  Farmers'  Bulletins,  Nos.  249, 
389;  Wilson  &  Warburton,  pp.  135-172. 

10.  Other  foodstuffs  —  Bigelow,  pp.  100-110,460-462,474-476;  Conn, 
pp.  56-99;    Freeman  &  Chandler,  pp.  65-113;   Kinne  &  Cooley 
(Foods),  pp.  126-137,  187-208. 

11.  Origin  and  nature  of  soils  —  (Any  good  text  in  Agriculture.) 

12.  Soil  conditions  for  plant  growth  —  Bigelow,  pp.  85-88,  97-100; 
Coulter  &  Patterson,  pp.  280-287 ;  Farmers'  Bulletins,  Nos.  245, 
266,  408;  Lipman,  pp.  144-263;  Warren,  pp.  76-87,  91-95. 


212  APPENDIX 

13.   Usefulness  of  plants  to  man  —  Farmers'  Bulletins,  Nos.  173,  358; 
Freeman  &  Chandler,  pp.  278-297. 

XIII.   WORK  AND  MACHINES 
1 

1 .  Meaning  of  the  terms  work  and  energy  —  (Any  good  text  in  Physios. ) 

2.  Classes  of  levers  —  (Any  good  text  in  Physics.) 

3.  Pulleys —  (Any  good  text  in  Physics.) 

XIV.  MAGNETISM  AND  ELECTRICITY 

1.  Electro-magnets  —  Brownell  (Physics),  pp.  84-85,  129.     (Any  good 

text  in  Physics.) 

2.  Electricity  and  chemical  changes  —  (Any  good  texts  in  Physics  and 

Chemistry.) 

XV.  PHENOMENA  OF  LIGHT 

1.  Shadows  and  eclipses — (Any  good  texts  in  Astronomy,  Physical 

Geography,  and  Physics.) 

2.  Images  by  reflection  —  Brownell  (Physics),  pp.  71-74.     (Any  good 

text  in  Physics.) 

3.  Color  phenomena  — Hooker  (Part  III),  Chaps.    XXVII-XXVIII. 

(Any  good  text  in  Physics.) 

XVI.  THE  EARTH  AS  A  PLANET 

1.  Day  and  night  and  the  earth's  rotation —  (Any  good  texts  in  As- 

tronomy, and  Physical  Geography.) 

2.  Rotation  combined  with  revolution  and  changes  in  seasons  —  Tarr, 

pp.    397-401.     (Any    good    texts    in    Astronomy,    and    Physical 
Geography.) 

3.  The  moon  and  its  phenomena  —  Crawford,  pp.   185-187.     (Any 

good  text  in  Astronomy.) 

4.  Time  and  time-keeping,  and  standard  time  —  (Any  good  texts  in 

Astronomy,  and  Physical  Geography.) 

XVII.  THE  HEAVENS 
Tarr,  1-6.     (Any  good  text  in  Astronomy.) 


INDEX 


Accidents,  90-94,  122. 

Acids,  97-100. 

Adenoids,  (>. 

Air  currents,  59-62. 

Air,  weight  of,  58-59. 

Albumen,  126,  153. 

Alcohol,  34-35,  92. 

Amusements,  33-34,  89. 

Antiseptic,  22. 

Antitoxin,  22. 

Apple  raising,  146-150. 

Artesian  wells,  27. 

Atmosphere,  52-62. 

Atmospheric    moisture,    42-44,    59- 

61. 
Atmospheric  pressure,  54-62,  75-76. 


Bacteria,  20,  32. 

Bacteriology,  20. 

Baking  powder,  153. 

Barometer,  55-56,  59-61. 

Base,  97-100. 

Bathroom,  81. 

Bedrooms,  13,  81. 

Birds,  115. 

Blood,  18,  20,  48. 

Blood  poisoning,  22. 

Bones,  2. 

Buds,  108-109,  112-113. 

Burns,  90. 

Business  ability,   101,   116-121,   144, 

150. 
Butter,  134-136. 

C 

Canning,  31,  136-137,  146. 
Carbonates,  98-100. 
Carbon  dioxide,  11,  98-100. 


Cells,  32. 

battery,  167,  169-171. 
Chemical  changes,  9-10,  46,  94-100, 

169-170. 

Chemical  equations,  98-99,  170. 
Chemistry  of  cleaning,  96—97. 
Cisterns,  28. 
Clay,  154-155. 
Climate,  73-76. 
Clocks,  190-192. 
Clothing,  18,  87. 
Color  phenomena,  177-179. 
Combustion,  9-12,  90. 
Condensation,  ,42—44. 
Constellations,  193-195. 
Corn,  studies  on,  111,  138-146. 
Cost  of  living,  84-89. 
Cow,  the,  132-133. 
Cyclone,  62,  65. 


I) 


Dairying,  134-135. 
Day  and  night,  180-183. 

relative  lengths  of,  183,  185. 
Density,  38,  52,  54,  58-62. 
Diffusion,  44—18. 
Disinfection,  24,  96. 
Drugs,  use  of  35. 
Dust  in  relation  to  health,  95. 


E 


Eclipses,  173-175. 
Eggs,  125-126,  128-129. 
Electric  bell,  168. 
Electricity,  167-171. 
Electrolyte,  171. 
Employers'  liability,  93.  ' 
Energy,  160-162. 

of  the  human  body,  17,  32-34. 
Erosion,  49-51. 
Eye,  6-8. 


213 


214 


INDEX 


Fermentation,  94-95. 

Fire  extinguisher,  91. 

Fires,  90-92 

Flame,  10-11. 

Flies,  26,  30. 

Food  elements,   126,   135-137,   152- 

153. 

Food  preservatives,  31,  94,  137. 
Food  supply,  84-86,   102-105,    125- 

126,  133-137,  151-153. 
Forces,  38-40,  44-46. 
Fruits,  146-147,  149. 
Fulcrum,  162-163. 


Gardening,  86,  101-105. 
Germination,  142-143. 
Germs,  20-23. 
Growth,  32,  37. 

H 

Habits,  34-35,  37. 

Hand,  1-3. 

Health,  19-37,  122-123. 

Heat  equator,  61. 

Heat  from  the  sun,  72-74. 

Heating  plants,  83-84. 

Heavens,  the,  193-197. 

Hen,  the,  124-125. 

"Highs"  and  "lows,"  60-62,  65-68 

Horizon,  181-182. 

Horse,  the,  129-132. 

House,  rooms  of,  77-84. 


Images  by  reflection,  175-177. 

Incubators,  128. 

Inertia,  39. 

Infection,  20-29,  95. 

Irrigation,  65. 

Isobars,  65-68 

Isotherms,  65-68. 


Joints,  2. 


sundry,  83. 

eaves  of  plants,  106,  108,  112-114. 
Covers,  162-163. 
,ife,  31-32. 
jungs,  14-16 

M 

Machines,  160-162. 
Magnets,  167-171. 
Matter,  38-40. 

properties  of,  38-42,  51-53. 
Meat,  86,  133. 
Milk,  134-137. 
VIolecular  motion,  45-48. 
Molecules,  39. 
Moon,  the,  185-189. 
Mosquitoes,  26,  30. 
Mouth,  3-6. 
Muscles,  1-5,  33-34. 


N 


Narcotics,  34-36. 


Occupations,  101-102,  116-119. 

for  children,  101-102,  119. 
Osmosis,  46-48. 
Oxidation,  9-12,  17. 
Oxygen,  9-14. 

P 

Parallels  of  latitude,  182,  184. 

Patent  medicines,  36. 

Pendulum,  189-191. 

Perspiration,  17-18. 

Phases  of  the  moon,  186-189. 

Planets,  the,  174-175,  195-197. 

Plant  studies,  105-114,  147-148. 

Plants,  usefulness  of,  157-159. 

Plumbing,  78. 

Poultry,  126-129. 

Properties  of  matter,  38-42,  52-53. 

Protein,  126,  153. 

Protoplasm,  31. 

Pulleys,  163-166. 

Pumps,  56-57. 

Pure  foods,  26,  31. 


INDEX 


215 


Q 


Quarantine,  23. 


Rainfall,  42-43,  64,  75-76. 

Rats,  30,  83. 

Recreation,  33-34,  89. 

Reflection  of  light,  175-178. 

Refraction  of  light,  177-178. 

Rents,  87-88. 

Respiration,  14-17. 

Revolution,  of  bodies,  173-175,  183- 

189. 

Roots,  105-106,  111-112,  139. 
Rotation  of  bodies,  180-185. 
Rubber,  159. 


Salt,  97-100. 
Sand,  154-156. 
Sanitation,  24-31,  122-123. 
Satellites,  175,  197. 
School  attendance,  120-123. 
Secretions,  6,  18. 
Serum,  21-22. 
Shadows,  172-175. 
Sickness,  19-26,  29. 

prevention  of,  19,  36. 
Silos,  146. 
Siphon,  57-58. 
Skin,  3,  18. 
Soap,  96-97,  137. 
Soil  air,  157. 
Soil,  cultivation  of,  104,  143. 

nature  of,  154-155. 
Soil  waters,  155-157. 
Solar  system,  195-197. 
Solution,  44-48. 
Spectrum,  177-179. 
Standard  time,  192. 
Stars,  193-197. 
Sterilization,  22. 
Stimulants,  34-36. 


Streams,  study  of,  48-51. 
Stress  and  strain,  39-40. 


Teeth,  5-6. 

Telegraph,  key  and  sounder,  168-169. 

Temperature,  69-76. 

of  body,  17-19. 
Theory,  160. 
Thermometers,  69-70. 
Time-keeping,  189-192. 
Toxins,  21-22. 

Transportation,  117-118,  144,  147. 
Trees,  for  fruit,  106-107. 

planting  of,  105-107,  147-148. 

pruning  of,  107. 

spraying  of,  149. 

studies  of,  107-111. 
Tuberculosis,  13-14. 
Typhoid,  23. 

U 
Universe,  196. 

V 

Valleys,  49-51. 
Vapor,  10,  43,  90. 
Vaporization,  42—44. 

heat  of,  43-44. 
Ventilation,  12-14. 

W 

Wage  earning,  119-121. 
Water,  11,  41-44,  96. 
Water  supply,  27-29 
Weather,  63-68,  73-76. 
Weather  forecasts,  64,  76. 
Weather  maps,  65-68. 
Wells,  27-28. 
Wheat,  150-151. 
Wheelwork,  190-191. 
Wind,  53,  60-62,  75-76. 
Work,  162. 

Z 
Zenith,  60. 


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